condition mean min max ZT0-3 38.827725 37.5454 40.11005 ZT4-7 25.2833 25.2833 25.2833 ZT8-11 16.938650000000003 16.938650000000003 16.938650000000003 ZT12-15 0 0 0 ZT16-19 17.6338 17.6338 17.6338 ZT20-23 26.44265 26.44265 26.44265