condition mean min max ZT0-3 4.363814337 3.1202338189999996 5.607394855000001 ZT4-7 4.954073015750001 4.912590591000001 4.9955554405 ZT8-11 4.41346520725 3.8068159985 5.020114416 ZT12-15 2.91433449075 2.7211320425 3.107536939 ZT16-19 2.71585920225 2.6002597405 2.831458664 ZT20-23 1.78863125725 1.647214102 1.9300484125000001