condition mean min max ZT0-3 3.6157233333333334 0.0 7.1295 ZT4-7 6.49175 6.49175 6.49175 ZT8-11 0.0 0.0 0.0 ZT12-15 14.109175 10.22725 17.9911 ZT16-19 9.66826 9.66826 9.66826 ZT20-23 7.1835 7.1835 7.1835