condition mean min max ZT0-3 9.410747 9.410747 9.410747 ZT4-7 9.4649275 9.4649275 9.4649275 ZT8-11 9.893191999999999 9.893191999999999 9.893191999999999 ZT12-15 9.2999015 9.2999015 9.2999015 ZT16-19 9.784558 9.784558 9.784558 ZT20-23 9.292809 9.292809 9.292809