condition mean min max ZT0-3 1.0125908333333333 0.3388625 1.50037 ZT4-7 0.573015 0.573015 0.573015 ZT8-11 1.0406505 1.0406505 1.0406505 ZT12-15 1.1794302499999998 0.8713255 1.4875349999999998 ZT16-19 1.98044 1.98044 1.98044 ZT20-23 1.694925 1.694925 1.694925