condition mean min max ZT0-3 1.44317187 0.967969128 1.918374612 ZT4-7 1.927433686 1.7994432865 2.0554240855000003 ZT8-11 1.9339643175 1.8173317225 2.0505969125 ZT12-15 1.6469285745 1.493304936 1.800552213 ZT16-19 1.8030103065 1.6452396999999999 1.9607809130000002 ZT20-23 3.1881696345 2.761417797 3.614921472