condition mean min max ZT0-3 53.405664 53.405664 53.405664 ZT4-7 57.8290925 57.8290925 57.8290925 ZT8-11 57.6908895 57.6908895 57.6908895 ZT12-15 55.966037 55.966037 55.966037 ZT16-19 52.0021825 52.0021825 52.0021825 ZT20-23 51.715383 51.715383 51.715383