OP's hyperbole took it too far by saying "good programmer". But if you change it just "top one percent programmer", it might not be too much of an exaggeration. Before I also get banned, I want to clarify that there's a difference between:

- "it's hard to find a woman programmer in the top 1%" because women can't be good programmers due to their biology

- "it's hard to find a woman programmer in the top 1%" because our society failed to train and produce them

The second statement isn't inherently sexist, it's just an observation of the poor state of our world.

If you're familiar with programming/math competitions you'll know that there are not many female represented there even after taking into account their smaller population: http://www.topcoder.com/tc?module=AlgoRank. There are probably 500 "red" coders (which is roughly the top 1%) but with probably less than a handful who are female. All you need is a username to compete so it's pretty objective and gender-blinded.

So it seems exceptional female programmers are simply not being produced even as early as high school and college level. Google interviews are very similar to those competition so I assume their data will also uncomfortably show this.