condition mean min max ZT0-3 6.069315 6.069315 6.069315 ZT4-7 8.304770000000001 8.304770000000001 8.304770000000001 ZT8-11 3.93016 3.93016 3.93016 ZT12-15 3.1154650000000004 3.1154650000000004 3.1154650000000004 ZT16-19 4.103655 4.103655 4.103655 ZT20-23 5.757455 5.757455 5.757455