condition mean min max ZT0-3 3.4248483333333333 0.71163 6.27238 ZT4-7 6.016159999999999 6.016159999999999 6.016159999999999 ZT8-11 5.228125 5.228125 5.228125 ZT12-15 11.423937500000001 10.215415 12.63246 ZT16-19 12.661735 12.661735 12.661735 ZT20-23 12.336654999999999 12.336654999999999 12.336654999999999