Here are the numbers for one of my sites, not related to IT in any way:

    Google   94.3%
    Yahoo     2.6%
    Bing      1.8%
    Yandex    0.63%
    Ask       0.37%
    AOL       0.23%

EDIT:

Here's another non-IT site with 13 million monthly visits:

    Google   89.9%
    Yahoo     6.4%
    Bing      2.96%
    Ask       0.37%
    AOL       0.21%
    Yandex    0.12%