condition mean min max ZT0-3 24.887851 24.887851 24.887851 ZT4-7 15.038333999999999 15.038333999999999 15.038333999999999 ZT8-11 12.920020999999998 12.920020999999998 12.920020999999998 ZT12-15 14.3399675 14.3399675 14.3399675 ZT16-19 14.784111 14.784111 14.784111 ZT20-23 13.6959525 13.6959525 13.6959525