condition mean min max ZT0-3 9.357895 9.357895 9.357895 ZT4-7 6.7002299999999995 6.7002299999999995 6.7002299999999995 ZT8-11 5.175385 5.175385 5.175385 ZT12-15 7.034015 7.034015 7.034015 ZT16-19 12.8082 12.8082 12.8082 ZT20-23 9.479285 9.479285 9.479285