condition mean min max ZT0-3 22.520725 21.29805 23.7434 ZT4-7 28.928350000000002 28.928350000000002 28.928350000000002 ZT8-11 22.72915 22.72915 22.72915 ZT12-15 0 0 0 ZT16-19 27.0275 27.0275 27.0275 ZT20-23 29.8828 29.8828 29.8828