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