LinkedIn users by countryLinkedIn has around 347 million registered users, and more than 75 percent of its new members come from outside the United States. The professional social network reported a 25 percent year-over-year increase in membership during the final quarter of 2014. While some countries \u2014 including LinkedIn's home market, the United States \u2014 are saturated with users, others \u2014 such as China \u2014 represent a massive growth opportunity for the company. The following slides list the top 17 countries in the world with the most registered LinkedIn members.The United States: 111 million LinkedIn usersImage by ShutterstockMore than one in three U.S. residents are registered members of LinkedIn. LinkedIn's 111 million registered U.S. members equal roughly 54 percent of the country's working age (15 years to 64 years) population of approximately 204 million people. The total U.S. population is 318.9 million, but the labor force is much smaller.India: 28 million LinkedIn usersImage by ShutterstockIndia, the country with the second most LinkedIn users (28 million), is also the second most populated country in the world, with more than 1.2 billion people. India's economy, the 10th largest by gross domestic product (GDP), is one of the fastest growing in the world. The country's working-age population is roughly 700 million people today.Brazil: 20 million LinkedIn usersImage by ShutterstockBrazil, the world's fifth largest country by landmass and population, boasts the seventh largest economy by GDP. LinkedIn's 20 million registered members in the country represent roughly 10 percent of Brazil's total population (202.8 million people) and almost 17 percent of its working age population, according to the World Bank.The United Kingdom: 17 million LinkedIn usersImage by ShutterstockSlightly more than one in four people living in the United Kingdom are registered LinkedIn members. It is the 22nd most populous country, with approximately 64.1 million inhabitants, 17 million of which are LinkedIn users. The country's working age population is about 40 million, and the U.K. economy is the sixth largest in the world.Canada: 10 million LinkedIn usersImage by ShutterstockAlmost half of all working-age individuals living in Canada are registered members of LinkedIn. The country's economy is the 11th largest in the world. It boasts a population of 35.7 million people, and more than 24 million of them are of working age. LinkedIn has 10 million registered members in Canada.France: 9 million LinkedIn usersImage by ShutterstockLinkedIn's sixth largest country by users is the fifth-largest economy in the world. France boasts a population of 66.6 million people, and roughly 14 percent of them (9 million people) use LinkedIn.China: 8 million LinkedIn usersImage by ShutterstockThe world's most populous country represents one of LinkedIn's greatest opportunities for growth. China is the second largest economy in the world, with a population of 1.35 billion people. LinkedIn's user base in China doubled to 8 million people in 2014, and its working-age population is a staggering 919.5 million people.Mexico: 7 million LinkedIn users Image by ShutterstockLinkedIn's eighth largest market is the world's 15th biggest economy. Mexico's population of 113 million people makes it the 11th most populous overall, second most populous in Latin America and the most populated Spanish-speaking country in the world. It has 7 million registered LinkedIn users.Italy: 7 million LinkedIn usersImage by ShutterstockOut of 61 million people who call Italy home, roughly 39.6 million are of working age, and 7 million of them use LinkedIn. Italy's economy is the eighth largest in the world and third largest in the Eurozone. Italy is also the world's largest wine producer and the sixth largest manufacturing country.Spain: 6 million LinkedIn usersImage by ShutterstockSpain's population has been in decline since it peaked in 2012. The world's 13th largest economy has a total population of 46.5 million people. The country's unemployment rate is among the highest in Europe at 23.6 percent. LinkedIn has more than 6 million users in Spain, and that's about 13 percent of the total population.Australia: 6 million LinkedIn usersImage by ShutterstockRoughly one in four people living in Australia is a registered member of LinkedIn. The world's twelfth largest economy has a total population of 23.8 million people, and 6 million of them use LinkedIn. Australia has the fifth highest per capita income in the world.Germany, Austria and Switzerland: 6 million LinkedIn usersImage by ShutterstockLinkedIn groups the German-speaking regions of Germany, Switzerland and Austria together, and the combined locations surpassed 6 million total LinkedIn members in February. Germany is the fourth-largest economy in the world and the third-largest importer and exporter of goods, with a population of 80.7 million people. Austria is the 28th largest economy in the world, and it has a population of 8.5 million people. Switzerland is the twentieth most powerful economy in the world with a population of 8.2 million people.Netherlands: 5 million LinkedIn usersImage by ShutterstockThe Netherlands is one of the most densely packed nations in the world, with a population of 16.9 million people. It is the 17th largest economy in the world, generating the 13th highest per capita income. Nearly 50 percent of the country's working-age population, or 5 million people, are registered LinkedIn users.Colombia: 4 million LinkedIn usersImage by ShutterstockColombia is the 31st largest economy in the world, with a population of 48 million people. LinkedIn's in-market user base of 4 million people represents almost 13 percent of the country's working-age population. Colombia is also the third most populous country in Latin America, and it is home to the third largest number of Spanish speakers in the world.Argentina: 4 million LinkedIn usersImage by ShutterstockArgentina's population of 42.6 million people powers the world's 21st largest economy. More than 4 million people, or 15 percent of the country's working age population, use LinkedIn.