condition mean min max ZT0-3 3.663075 3.663075 3.663075 ZT4-7 2.7136899999999997 2.7136899999999997 2.7136899999999997 ZT8-11 1.4972599999999998 1.4972599999999998 1.4972599999999998 ZT12-15 1.1296445 1.1296445 1.1296445 ZT16-19 4.82822 4.82822 4.82822 ZT20-23 3.83588 3.83588 3.83588