condition mean min max ZT0-3 40.11311666666666 37.262 43.96055 ZT4-7 26.332549999999998 26.332549999999998 26.332549999999998 ZT8-11 18.76455 18.76455 18.76455 ZT12-15 29.238950000000003 27.2486 31.229300000000002 ZT16-19 24.849200000000003 24.849200000000003 24.849200000000003 ZT20-23 36.74505 36.74505 36.74505