condition mean min max ZT0-3 15.443383 15.443383 15.443383 ZT4-7 16.453678500000002 16.453678500000002 16.453678500000002 ZT8-11 16.424109 16.424109 16.424109 ZT12-15 16.807935999999998 16.807935999999998 16.807935999999998 ZT16-19 18.2680915 18.2680915 18.2680915 ZT20-23 18.033016 18.033016 18.033016