Comments view limited to 20 results – any way to increase to 50 or 100?

Each day I manually delete the spam posted on my blog. The comments view allows a maximum of 20 comments in the view. When I have 200 spam entries – I need to click through 10 times to get rid of it all.

Is there a way I can view 50 or 100 comments in the wordpress admin window at a time?