What percentage of hands do you expect to win??

This is a question I've been wondering about. You've got 10 people at a table. You each have an equal chance of winning any given hand, so should you expect to win about 10% of hands in the long run? The reason I ask is that in the past month I've won maybe 4 - 5%. The month before that it was about 10%. Does this confirm my fears that I've hit a downswing? What are your stats like? I'm wondering what value should be expected here.