I just had a look myself:
For BibleDownloader, 21% of lines contain comments
For BlandAltmanPlot, 38% of lines contain comments
For ComputeNonCryptHash, 34% of lines contain comments
For ETA_disp, 55% of lines contain comments
For findND, 44% of lines contain comments
For getUTC, 28% of lines contain comments
For GetWritableFolder, 34% of lines contain comments
For ifversion, 47% of lines contain comments
For isnetavl, 36% of lines contain comments
For JSON, 29% of lines contain comments
For maximize, 42% of lines contain comments
For minify, 39% of lines contain comments
For PhotoAnnotation, 33% of lines contain comments
For point_to_line_distance, 62% of lines contain comments
For readdicomfolder, 31% of lines contain comments
For readfile, 36% of lines contain comments
For regexp_outkeys, 43% of lines contain comments
For RegGrow, 37% of lines contain comments
For save2mat, 27% of lines contain comments
For sqlite3, 34% of lines contain comments
For text2im, 32% of lines contain comments
For WBM, 33% of lines contain comments
For WindowLevel, 44% of lines contain comments
As with your code, this includes the documentation at the start of the function and averages out to 37.4%. I used a slightly different strategy to count the comments (using the comment stripper I wrote for minify). The resulting drop-in replacement for ProcessOneFile is attached.