Reducing the number of circles in one row?

Hi i would like to know how you can reduce the number of circles/pictures in one row!
As you can see on my site there are 5 images in the first row and only 1 in the second row. Is there a possibility to limit the number of images to 3 in one row?

This is my site: http://profstyle.bplaced.net/wordpress/teamkontakt/