Though I cannot answer this accurately, you'll find the songwriter gets alot more than the artist in most cases. this was typified when two of the smiths took morrissey to court to try and recoup some of the bands huge earnings for themselves when they realised him and Johnny Marr got all the money.
There is also an interesting piece of the back of a Steve Albini article about how f**ked the record industry is and how the artist sees nothing of the money they earn on a single. I'll link it if i can find it again.
This is really pedantic now.....but you'll also find that a 1.99 single is more of a marketing gimmick and the artist probably sees none of it.
Usual cut would be about 15% songwriter......7-8% artist