condition mean min max ZT0-3 7.886606 7.886606 7.886606 ZT4-7 9.7205925 9.7205925 9.7205925 ZT8-11 8.34037 8.34037 8.34037 ZT12-15 9.389881500000001 9.389881500000001 9.389881500000001 ZT16-19 9.910013 9.910013 9.910013 ZT20-23 9.2199125 9.2199125 9.2199125