pass1 - making usageList (24 chroms): 85 millis pass2 - checking and writing primary data (599547 records, 3 fields): 557 millis pass1 - making usageList (24 chroms): 52 millis pass2 - checking and writing primary data (361723 records, 3 fields): 342 millis pass1 - making usageList (24 chroms): 26 millis pass2 - checking and writing primary data (186051 records, 3 fields): 176 millis pass1 - making usageList (24 chroms): 16 millis pass2 - checking and writing primary data (111374 records, 3 fields): 106 millis