condition mean min max ZT0-3 3.4672066666666668 0.885 5.99389 ZT4-7 0.81269 0.81269 0.81269 ZT8-11 4.274595 4.274595 4.274595 ZT12-15 5.3769375 3.6375900000000003 7.1162849999999995 ZT16-19 0.826995 0.826995 0.826995 ZT20-23 9.192295 9.192295 9.192295