condition mean min max ZT0-3 1.0823415 0.5761645 1.3862450000000002 ZT4-7 1.07919 1.07919 1.07919 ZT8-11 1.0965500000000001 1.0965500000000001 1.0965500000000001 ZT12-15 2.6773 2.244955 3.109645 ZT16-19 2.1771149999999997 2.1771149999999997 2.1771149999999997 ZT20-23 2.21442 2.21442 2.21442