condition mean min max ZT0-3 6.622864999999999 6.29268 6.953049999999999 ZT4-7 5.494465 5.494465 5.494465 ZT8-11 8.662875 8.662875 8.662875 ZT12-15 0 0 0 ZT16-19 7.3976500000000005 7.3976500000000005 7.3976500000000005 ZT20-23 6.29581 6.29581 6.29581