pass1 - making usageList (24 chroms): 151 millis pass2 - checking and writing primary data (1054324 records, 3 fields): 938 millis pass1 - making usageList (24 chroms): 92 millis pass2 - checking and writing primary data (646290 records, 3 fields): 586 millis pass1 - making usageList (24 chroms): 46 millis pass2 - checking and writing primary data (320706 records, 3 fields): 320 millis pass1 - making usageList (24 chroms): 26 millis pass2 - checking and writing primary data (190267 records, 3 fields): 186 millis