condition mean min max ZT0-3 4.10975 4.10975 4.10975 ZT4-7 3.59842 3.59842 3.59842 ZT8-11 4.077005 4.077005 4.077005 ZT12-15 4.14401 4.14401 4.14401 ZT16-19 5.50493 5.50493 5.50493 ZT20-23 4.80261 4.80261 4.80261