condition mean min max ZT0-3 1.6727699999999999 1.6727699999999999 1.6727699999999999 ZT4-7 2.36089 2.36089 2.36089 ZT8-11 2.73028 2.73028 2.73028 ZT12-15 2.224165 2.224165 2.224165 ZT16-19 1.0702985 1.0702985 1.0702985 ZT20-23 1.3332199999999998 1.3332199999999998 1.3332199999999998