I am trying to calculate the total exonic length (in bp) in order to see where the coding-noncoding ratio of roughly 1% to 99% comes from. We know all chromosomes total about 3 billion base pairs. So Is it correct to assume that coding regions would total about 30 million base pairs? I am looking at the numbers in the sources below, but nothing there adds up...
Take numbers from NCBI annothation for example; specifically
no matter how i count i can't get the expected ratio... What am doing wrong?