Why do people have abortions?

I feel like this question is worth asking because I do not understand why people have abortions. Now, in 2011, what are your thoughts and perspectives of abortion, why or why not?

I’m not looking to get into a heated argument but personally I am pro-life and I am wondering why some are pro-choice.

I would like to point out that some of you may be thinking the situation of rape, but that is only accountable of around 1% of reasons people claimed for abortion. I am thinking about the other 99%.