condition mean min max ZT0-3 14.129574999999999 11.95065 16.3085 ZT4-7 20.6754 20.6754 20.6754 ZT8-11 21.45915 21.45915 21.45915 ZT12-15 0 0 0 ZT16-19 21.352649999999997 21.352649999999997 21.352649999999997 ZT20-23 18.85255 18.85255 18.85255