condition mean min max ZT0-3 6.420051666666667 4.755165 7.8746849999999995 ZT4-7 6.903694999999999 6.903694999999999 6.903694999999999 ZT8-11 9.246755 9.246755 9.246755 ZT12-15 5.764795 5.2138100000000005 6.31578 ZT16-19 10.244735 10.244735 10.244735 ZT20-23 10.786249999999999 10.786249999999999 10.786249999999999