condition mean min max ZT0-3 8.607005000000001 8.487825 8.726185 ZT4-7 7.6086599999999995 7.6086599999999995 7.6086599999999995 ZT8-11 33.4549 33.4549 33.4549 ZT12-15 0 0 0 ZT16-19 22.0458 22.0458 22.0458 ZT20-23 16.04405 16.04405 16.04405