condition mean min max ZT0-3 11.5587335 11.441622575 11.675844425000001 ZT4-7 13.737091753333333 13.560870959999999 13.913312546666667 ZT8-11 14.12151246 12.70491142 15.5381135 ZT12-15 15.975651125 15.8852938 16.06600845 ZT16-19 16.0619241 15.603915023333334 16.519933176666665 ZT20-23 13.927644815 13.5534078 14.301881830000001