condition mean min max ZT0-3 13.140566666666667 11.185500000000001 14.2499 ZT4-7 13.33285 13.33285 13.33285 ZT8-11 12.562899999999999 12.562899999999999 12.562899999999999 ZT12-15 26.123075 25.71065 26.5355 ZT16-19 20.70445 20.70445 20.70445 ZT20-23 18.7269 18.7269 18.7269