condition mean min max ZT0-3 33.734554 33.734554 33.734554 ZT4-7 44.210672 44.210672 44.210672 ZT8-11 48.0241355 48.0241355 48.0241355 ZT12-15 50.005523499999995 50.005523499999995 50.005523499999995 ZT16-19 44.8218895 44.8218895 44.8218895 ZT20-23 40.364179500000006 40.364179500000006 40.364179500000006