condition mean min max ZT0-3 5.213493333333333 3.1189850000000003 6.33889 ZT4-7 1.99572 1.99572 1.99572 ZT8-11 1.5916350000000001 1.5916350000000001 1.5916350000000001 ZT12-15 2.0294475 1.95715 2.1017449999999998 ZT16-19 1.75253 1.75253 1.75253 ZT20-23 3.23431 3.23431 3.23431