As explained here, I expected about one-third of UKIP's 2014 intake of 24 MEP's to have resigned by this year, i.e. down to 16.
This is all rearranging deckchairs now, so it doesn't really matter, but they appear to have beaten their target, from Wiki:
UKIP has 15 members in the European Parliament, with representatives in eleven of the twelve European Parliament constituencies in the UK. Twenty-four UKIP representatives were elected in the 2014 election, but ten have since defected.
"Defected" is a bit harsh. One of them resigned and UKIP appointed a replacement MEP. Most of them quit out of principle, see e.g. here or because another MEP beat them up.
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