condition mean min max ZT0-3 27.454745 27.454745 27.454745 ZT4-7 17.0621985 17.0621985 17.0621985 ZT8-11 15.8596495 15.8596495 15.8596495 ZT12-15 14.293524000000001 14.293524000000001 14.293524000000001 ZT16-19 19.203758999999998 19.203758999999998 19.203758999999998 ZT20-23 16.785691 16.785691 16.785691