condition mean min max ZT0-3 21.1661 21.1661 21.1661 ZT4-7 14.90715 14.90715 14.90715 ZT8-11 14.2889 14.2889 14.2889 ZT12-15 18.167450000000002 18.167450000000002 18.167450000000002 ZT16-19 23.97615 23.97615 23.97615 ZT20-23 23.2169 23.2169 23.2169