condition mean min max ZT0-3 11.987575 11.083400000000001 12.89175 ZT4-7 12.692599999999999 12.692599999999999 12.692599999999999 ZT8-11 11.902249999999999 11.902249999999999 11.902249999999999 ZT12-15 0 0 0 ZT16-19 14.6596 14.6596 14.6596 ZT20-23 12.59395 12.59395 12.59395