condition mean min max ZT0-3 3.5692133333333333 2.997275 4.33156 ZT4-7 6.853695 6.853695 6.853695 ZT8-11 14.9627 14.9627 14.9627 ZT12-15 16.8126 16.7146 16.9106 ZT16-19 17.56835 17.56835 17.56835 ZT20-23 12.687619999999999 12.687619999999999 12.687619999999999