condition mean min max ZT0-3 19.734 15.337700000000002 24.1303 ZT4-7 7.5358350000000005 7.5358350000000005 7.5358350000000005 ZT8-11 20.028399999999998 20.028399999999998 20.028399999999998 ZT12-15 0 0 0 ZT16-19 15.73095 15.73095 15.73095 ZT20-23 9.90478 9.90478 9.90478