Python code to grab Penn World Tables data

For any interested parties, I wrote a small python script to download the Penn World Tables dataset and convert it into a Pandas Panel.  Code passed all of my tests, but can't claim that it is industrial strength.

To test out the code, I put together a quick set of layered histograms for global real GDP per capita growth rates from 1951 to 2010.  Result...

The number of countries for which data is available varies from around 50 in 1951 to roughly 190 in 2010.  Perhaps this means I should have normalized the above histogram?