condition mean min max ZT0-3 12.657903333333334 8.99576 15.57875 ZT4-7 7.8311 7.8311 7.8311 ZT8-11 6.419835 6.419835 6.419835 ZT12-15 8.6716675 7.681979999999999 9.661355 ZT16-19 10.98955 10.98955 10.98955 ZT20-23 14.481349999999999 14.481349999999999 14.481349999999999