condition mean min max ZT0-3 9.171676666666666 7.539405 10.83626 ZT4-7 5.196115000000001 5.196115000000001 5.196115000000001 ZT8-11 8.01366 8.01366 8.01366 ZT12-15 12.346125 12.22795 12.4643 ZT16-19 7.882099999999999 7.882099999999999 7.882099999999999 ZT20-23 11.0549 11.0549 11.0549