condition mean min max ZT0-3 1.829595 1.829595 1.829595 ZT4-7 1.416795 1.416795 1.416795 ZT8-11 1.425815 1.425815 1.425815 ZT12-15 1.544185 1.544185 1.544185 ZT16-19 1.5642049999999998 1.5642049999999998 1.5642049999999998 ZT20-23 1.61288 1.61288 1.61288