LONDON — Net migration to Britain has fallen to a three-year low as a growing number of European Union citizens have left the country following last year’s Brexit referendum.

Data released Thursday by the Office for National Statistics provides evidence that the uncertainty and economic jitters caused by Britain’s vote to quit the EU are deterring immigrants and sparking a ‘‘Brexodus.’’

The statistics office said net migration — the difference between arrivals and departures — was 246,000 in the year to March 31, a fall of 81,000 from a year earlier.

More than half the change was due to a decline of 51,000 people in net migration from the EU.

A total of 122,000 EU citizens left Britain in the year up until March, up 31,000 from the year before and the highest outflow in nearly a decade.

There was a particularly sharp rise in departures from citizens of the ‘‘EU Eight’’ — the eastern European nations that joined the bloc in 2004. Hundreds of thousands of Poles, Lithuanians, and other eastern Europeans moved to Britain to work after 2004.

More than 3 million nationals of other EU countries reside in Britain.

When Britain leaves the EU in March 2019, it will have the power to set restrictions on the movement of people from the EU, leaving many EU citizens uncertain about their future rights in Britain.