condition mean min max ZT0-3 5.067258333333333 4.793725 5.29972 ZT4-7 3.148765 3.148765 3.148765 ZT8-11 5.030195 5.030195 5.030195 ZT12-15 7.32536 7.09295 7.5577700000000005 ZT16-19 6.80808 6.80808 6.80808 ZT20-23 6.91037 6.91037 6.91037