condition mean min max ZT0-3 26.031605 26.031605 26.031605 ZT4-7 28.3286395 28.3286395 28.3286395 ZT8-11 27.506624000000002 27.506624000000002 27.506624000000002 ZT12-15 26.988941 26.988941 26.988941 ZT16-19 27.060741 27.060741 27.060741 ZT20-23 26.8464015 26.8464015 26.8464015