condition mean min max ZT0-3 14.967162545 14.19688055 15.73744454 ZT4-7 21.416954275000002 18.182399685 24.651508865 ZT8-11 41.54745712 34.84152424 48.253389999999996 ZT12-15 37.909561677499994 31.95043605 43.868687304999995 ZT16-19 35.10980724 34.63790388 35.5817106 ZT20-23 33.228817182499995 33.067360565 33.390273799999996