condition mean min max ZT0-3 4.057601666666667 2.24075 7.067399999999999 ZT4-7 8.19365 8.19365 8.19365 ZT8-11 7.980639999999999 7.980639999999999 7.980639999999999 ZT12-15 15.755749999999999 13.7516 17.7599 ZT16-19 7.5366800000000005 7.5366800000000005 7.5366800000000005 ZT20-23 2.920285 2.920285 2.920285