condition mean min max ZT0-3 50.681315 50.681315 50.681315 ZT4-7 36.4725575 36.4725575 36.4725575 ZT8-11 36.937845499999995 36.937845499999995 36.937845499999995 ZT12-15 43.178045999999995 43.178045999999995 43.178045999999995 ZT16-19 37.8121885 37.8121885 37.8121885 ZT20-23 56.5914255 56.5914255 56.5914255