condition mean min max ZT0-3 13.838830845 11.36000456 16.31765713 ZT4-7 8.9611550095 7.661247425 10.261062594 ZT8-11 11.9701255595 10.984988925 12.955262194 ZT12-15 12.7593756425 12.191777195 13.32697409 ZT16-19 15.4160714625 15.20900346 15.623139465 ZT20-23 19.090980107500002 18.15262805 20.029332165