condition mean min max ZT0-3 5.3970625000000005 5.198285 5.59584 ZT4-7 4.1107249999999995 4.1107249999999995 4.1107249999999995 ZT8-11 4.502649999999999 4.502649999999999 4.502649999999999 ZT12-15 0 0 0 ZT16-19 5.421435000000001 5.421435000000001 5.421435000000001 ZT20-23 5.1949950000000005 5.1949950000000005 5.1949950000000005