condition mean min max ZT0-3 8.066419999999999 8.066419999999999 8.066419999999999 ZT4-7 5.7571200000000005 5.7571200000000005 5.7571200000000005 ZT8-11 7.741075 7.741075 7.741075 ZT12-15 7.882365 7.882365 7.882365 ZT16-19 10.6511 10.6511 10.6511 ZT20-23 8.81908 8.81908 8.81908