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