pass1 - making usageList (24 chroms): 199 millis pass2 - checking and writing primary data (1299535 records, 3 fields): 1194 millis pass1 - making usageList (24 chroms): 104 millis pass2 - checking and writing primary data (614531 records, 3 fields): 565 millis pass1 - making usageList (24 chroms): 34 millis pass2 - checking and writing primary data (244150 records, 3 fields): 238 millis pass1 - making usageList (24 chroms): 20 millis pass2 - checking and writing primary data (133555 records, 3 fields): 135 millis