condition mean min max ZT0-3 21.625975 17.63925 25.6127 ZT4-7 21.4929 21.4929 21.4929 ZT8-11 16.37365 16.37365 16.37365 ZT12-15 0 0 0 ZT16-19 26.6458 26.6458 26.6458 ZT20-23 23.4407 23.4407 23.4407