condition mean min max ZT0-3 8.99113 8.99113 8.99113 ZT4-7 2.68611 2.68611 2.68611 ZT8-11 1.9555349999999998 1.9555349999999998 1.9555349999999998 ZT12-15 2.999825 2.999825 2.999825 ZT16-19 9.9903 9.9903 9.9903 ZT20-23 8.328373333333333 8.328373333333333 8.328373333333333