Around 17 percent of Swiss residents over the age of 15 holds two passports and in Canton Geneva, where the European headquarters of the United Nations is based, 45 percent are dual nationals, the Swiss government said Wednesday.

Among dual nationals, 64.4 percent became Swiss though naturalization while 36.6 percent obtained Swiss citizenship at birth, updated data from the Federal Statistics Office (FSO) shows.

Italians are the largest group, making up 24.7 percent of the total of those who have obtained Swiss citizenship through naturalization.

This group is followed by the French (around 11.2 percent of the total) and Germans, at around 7.8 percent.

"An acquisition of Swiss citizenship is when a foreign national obtains a Swiss passport," the FSO said.

Such a person is, after that, included in the population statistics of Swiss nationals.

Germans are the fastest growing group of dual nationals in Switzerland. In 2000, they accounted for just 2.3 percent of all naturalizations, while in 2017, this number jumped to 13.3 percent.

Interest among Italians is decreasing. In 2000, people of Italian nationality made up just over a quarter of naturalizations, while this had declined to 13 percent last year.