condition mean min max ZT0-3 168.8988889 168.8988889 168.8988889 ZT4-7 171.825 171.825 171.825 ZT8-11 158.3138889 158.3138889 158.3138889 ZT12-15 175.51 175.51 175.51 ZT16-19 169.2611111 169.2611111 169.2611111 ZT20-23 202.51222223333332 202.51222223333332 202.51222223333332