condition mean min max ZT0-3 16.803975 15.20575 18.4022 ZT4-7 15.12345 15.12345 15.12345 ZT8-11 31.1533 31.1533 31.1533 ZT12-15 0 0 0 ZT16-19 25.2158 25.2158 25.2158 ZT20-23 21.27505 21.27505 21.27505