I'm not sure what part of these statistics you're commenting on in particular. If you're amazed at how much experience the average open source developer has, it's worth pointing out that there's a lot of open source software development that is directly sponsored by enterprise-scale companies that use the software itself. E.g. companies that both use, and contribute to the Linux kernel such as Google, and Facebook. Another good example is Netflix and FreeBSD. Also relevant are processor manufacturers who contribute code relevant to their IP to GCC. It's really awesome seeing companies be good stewards of OSS.