pass1 - making usageList (24 chroms): 185 millis pass2 - checking and writing primary data (1247952 records, 3 fields): 1278 millis pass1 - making usageList (24 chroms): 92 millis pass2 - checking and writing primary data (640241 records, 3 fields): 586 millis pass1 - making usageList (24 chroms): 40 millis pass2 - checking and writing primary data (277510 records, 3 fields): 271 millis pass1 - making usageList (24 chroms): 25 millis pass2 - checking and writing primary data (157147 records, 3 fields): 189 millis