[CentOS] Percentage of CentOS coded in each language

Had a curious question about how much of Linux (as a usable 
distribution, not just the kernel) is coded in each language. I can find 
some older or vague references without citation that Linux is largely 
coded in C and C++, with a fraction of a percent coded in other languages.

While the source is available, I'm not sure how would one go about 
determining the percentage of CentOS coded in each language (either by 
lines of source code or by RPM package). Anyone have any suggestions for 
determining this info? Someone already have the answer?

Thanks,
--B