condition mean min max ZT0-3 8.16419921475 6.4546281225 9.873770307000001 ZT4-7 10.363360824 7.413074693 13.313646955 ZT8-11 15.35522052 12.6611646 18.04927644 ZT12-15 22.264354514999997 20.225133219999996 24.303575809999998 ZT16-19 27.3779715975 24.82109509 29.934848105 ZT20-23 31.3872053025 28.794446815 33.97996379