condition mean min max ZT0-3 39.734750000000005 39.734750000000005 39.734750000000005 ZT4-7 51.963499999999996 51.963499999999996 51.963499999999996 ZT8-11 30.951999999999998 30.951999999999998 30.951999999999998 ZT12-15 16.71015 16.71015 16.71015 ZT16-19 20.7943 20.7943 20.7943 ZT20-23 18.8857 18.8857 18.8857