condition mean min max ZT0-3 4.135075 4.08935 4.1808 ZT4-7 3.05701 3.05701 3.05701 ZT8-11 7.15901 7.15901 7.15901 ZT12-15 0 0 0 ZT16-19 6.6951149999999995 6.6951149999999995 6.6951149999999995 ZT20-23 4.985155000000001 4.985155000000001 4.985155000000001