condition mean min max ZT0-3 31.266426 31.266426 31.266426 ZT4-7 24.5707875 24.5707875 24.5707875 ZT8-11 16.6997735 16.6997735 16.6997735 ZT12-15 17.7755055 17.7755055 17.7755055 ZT16-19 18.1354655 18.1354655 18.1354655 ZT20-23 14.7907005 14.7907005 14.7907005