pass1 - making usageList (24 chroms): 247 millis pass2 - checking and writing primary data (1728686 records, 3 fields): 1650 millis pass1 - making usageList (24 chroms): 175 millis pass2 - checking and writing primary data (1068031 records, 3 fields): 994 millis pass1 - making usageList (24 chroms): 76 millis pass2 - checking and writing primary data (532081 records, 3 fields): 504 millis pass1 - making usageList (24 chroms): 43 millis pass2 - checking and writing primary data (317579 records, 3 fields): 285 millis