condition mean min max ZT0-3 7.748765000000001 7.6728499999999995 7.824680000000001 ZT4-7 6.66962 6.66962 6.66962 ZT8-11 4.4336199999999995 4.4336199999999995 4.4336199999999995 ZT12-15 0 0 0 ZT16-19 6.280645 6.280645 6.280645 ZT20-23 9.10428 9.10428 9.10428