condition mean min max ZT0-3 13.1102435575 11.440143935 14.780343180000001 ZT4-7 18.33434202 16.93710386 19.73158018 ZT8-11 17.88294438666667 16.64886707666667 19.11702169666667 ZT12-15 15.42095857 14.220867313333333 16.621049826666667 ZT16-19 11.810301192166666 11.47858084 12.142021544333334 ZT20-23 13.395120255 12.88801325 13.90222726