The figures also show a 67% rise in the number of EU nurses leaving the NMC's register: from 2,435 in 2015-16 to 4,067 in the last year.
Jeremy Hunt recently said he was "confident" EU staff in the NHS would be able to stay, but could not give a firm guarantee.
Liberal Democrat Health Spokesperson Judith Jolly commented:
“This is yet more evidence of a deeply worrying Brexodus of EU nurses from the NHS.
“Our health service is already overstretched and understaffed, it cannot afford to lose this many nurses especially as we approach another winter crisis.
“It is not good enough for the government to say it is confident NHS staff from the EU will be able to stay.
“Ministers must give a cast-iron guarantee that the European nurses and doctors who keep our health service afloat can stay here no matter what."
Local Liberal Democrat party official Frank Little added:
"This is another case of a Westminster policy over which we have no control impacting a major devolved matter in Wales. In addition to the uncertainty caused by Mrs May's decision to trigger Article 50 talks, there are also the economic barriers to much-needed professionals from the Commonwealth coming to the aid of our health service, barriers which Mrs May presided over when she was Home Secretary.
"It would help of course if Labour's Jeremy Corbyn and Carwyn Jones put up a robust defence of our membership of the EU and of the Commonwealth instead of appeasing the xenophobic element of their vote."