condition mean min max ZT0-3 6.9151802195 6.2921856169999995 7.538174822 ZT4-7 7.5314813965 5.8712217959999995 9.191740997 ZT8-11 16.118958124 13.943084943 18.294831305 ZT12-15 30.936078922500002 24.088218235 37.783939610000004 ZT16-19 49.373350085 41.434861285 57.311838885 ZT20-23 82.206825135 77.7951282 86.61852207