condition mean min max ZT0-3 11.970792 11.970792 11.970792 ZT4-7 9.8890375 9.8890375 9.8890375 ZT8-11 12.354032 12.354032 12.354032 ZT12-15 14.382334 14.382334 14.382334 ZT16-19 15.7886765 15.7886765 15.7886765 ZT20-23 21.9754425 21.9754425 21.9754425