condition mean min max ZT0-3 15.341971 15.341971 15.341971 ZT4-7 27.010032000000002 27.010032000000002 27.010032000000002 ZT8-11 24.4772595 24.4772595 24.4772595 ZT12-15 15.341971 15.341971 15.341971 ZT16-19 11.6384615 11.6384615 11.6384615 ZT20-23 11.591738 11.591738 11.591738