condition mean min max ZT0-3 9.73 9.73 9.73 ZT4-7 9.184444444333334 9.184444444333334 9.184444444333334 ZT8-11 7.812222222333333 7.812222222333333 7.812222222333333 ZT12-15 8.24 8.24 8.24 ZT16-19 6.978888889 6.978888889 6.978888889 ZT20-23 9.96888889 9.96888889 9.96888889