calculate a block size ratio by dividing {TAIL ~ a number} of block size correlation coefficients above a first threshold by {HEAD ~ a total number} of block size correlation coefficients 
calculate a block size ratio by dividing { TAIL ~ a number } of block size correlation coefficients above a first threshold by { HEAD ~ a total number } of block size correlation coefficients
OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH