condition mean min max ZT0-3 13.106178333333334 9.066485 15.4984 ZT4-7 8.490505 8.490505 8.490505 ZT8-11 8.11166 8.11166 8.11166 ZT12-15 12.550725 12.34695 12.7545 ZT16-19 12.3155 12.3155 12.3155 ZT20-23 16.1921 16.1921 16.1921