condition mean min max ZT0-3 21.087531 21.087531 21.087531 ZT4-7 18.4172415 18.4172415 18.4172415 ZT8-11 18.556413 18.556413 18.556413 ZT12-15 16.585312 16.585312 16.585312 ZT16-19 18.774908 18.774908 18.774908 ZT20-23 17.3357485 17.3357485 17.3357485