condition mean min max ZT0-3 7.324845 7.324845 7.324845 ZT4-7 8.817595 8.817595 8.817595 ZT8-11 4.132595 4.132595 4.132595 ZT12-15 4.70368 4.70368 4.70368 ZT16-19 8.327105 8.327105 8.327105 ZT20-23 6.286490000000001 6.286490000000001 6.286490000000001