condition mean min max ZT0-3 1.672975 1.3925550000000002 1.953395 ZT4-7 0.9298725 0.9298725 0.9298725 ZT8-11 1.694055 1.694055 1.694055 ZT12-15 0 0 0 ZT16-19 2.112055 2.112055 2.112055 ZT20-23 2.179385 2.179385 2.179385