condition mean min max ZT0-3 3.260055 3.260055 3.260055 ZT4-7 2.26269 2.26269 2.26269 ZT8-11 2.89184 2.89184 2.89184 ZT12-15 3.6778649999999997 3.6778649999999997 3.6778649999999997 ZT16-19 2.52983 2.52983 2.52983 ZT20-23 2.436135 2.436135 2.436135