condition mean min max ZT0-3 6.528758 6.528758 6.528758 ZT4-7 8.750638 8.750638 8.750638 ZT8-11 8.037892500000002 8.037892500000002 8.037892500000002 ZT12-15 8.036908 8.036908 8.036908 ZT16-19 7.61262 7.61262 7.61262 ZT20-23 7.2838695 7.2838695 7.2838695