condition mean min max ZT0-3 5.306241666666667 4.867165 5.602565 ZT4-7 3.6780150000000003 3.6780150000000003 3.6780150000000003 ZT8-11 3.53972 3.53972 3.53972 ZT12-15 3.2963025 2.65089 3.941715 ZT16-19 4.84168 4.84168 4.84168 ZT20-23 5.80987 5.80987 5.80987