condition mean min max ZT0-3 4.10768176025 3.474575752 4.740787768500001 ZT4-7 11.915362736 7.710626537 16.120098935 ZT8-11 34.6094413425 24.60960701 44.609275675 ZT12-15 24.0865195275 16.477119934999997 31.69591912 ZT16-19 10.96831167025 9.196662843 12.7399604975 ZT20-23 4.531295613499999 3.902732576 5.1598586509999995