What is the difference between votes cast and votes fulfilled on community wishlist stats? There are around one point five million votes fulfilled and five million votes cast. Can someone explain this?

"This feature sounds interesting. Let me vote for it." This adds one to the votes cast.
"This feature is completed and the wish is marked as complete." This moves all the votes from said wish to the fulfilled part.

In other words, votes cast are all the votes on the wishlist, votes fulfilled are only the votes on the wishes that are marked as complete.

Thanks.