condition mean min max ZT0-3 23.87795 21.5263 26.229599999999998 ZT4-7 28.9037 28.9037 28.9037 ZT8-11 16.1373 16.1373 16.1373 ZT12-15 0 0 0 ZT16-19 30.087 30.087 30.087 ZT20-23 28.80135 28.80135 28.80135