condition mean min max ZT0-3 6.66587 5.83933 7.4924100000000005 ZT4-7 14.2212 14.2212 14.2212 ZT8-11 29.37055 29.37055 29.37055 ZT12-15 0 0 0 ZT16-19 21.36695 21.36695 21.36695 ZT20-23 12.9896 12.9896 12.9896