condition mean min max ZT0-3 0.846723 0.846723 0.846723 ZT4-7 0.9007135 0.9007135 0.9007135 ZT8-11 0.8348515000000001 0.8348515000000001 0.8348515000000001 ZT12-15 1.3102049999999998 1.3102049999999998 1.3102049999999998 ZT16-19 2.69015 2.69015 2.69015 ZT20-23 2.270923333333333 2.270923333333333 2.270923333333333