condition mean min max ZT0-3 1.10188612575 0.235333768 1.9684384835 ZT4-7 3.8088523025 2.954507931 4.663196674 ZT8-11 5.385431667499999 4.534413237 6.236450097999999 ZT12-15 8.82471927675 7.313926024 10.3355125295 ZT16-19 7.04889526 6.758735189499999 7.3390553305 ZT20-23 9.07217491275 8.629202336999999 9.5151474885