condition mean min max ZT0-3 11.12417655975 6.026865389499999 16.22148773 ZT4-7 13.13803171 6.058355705 20.217707715 ZT8-11 34.7582448325 30.93992604 38.576563625 ZT12-15 51.3640439725 36.533365544999995 66.1947224 ZT16-19 57.767641095 54.404348315 61.130933875 ZT20-23 42.9413402 37.31953626 48.563144140000006