condition mean min max ZT0-3 3.6229316666666667 1.84605 4.9989 ZT4-7 2.01261 2.01261 2.01261 ZT8-11 1.475445 1.475445 1.475445 ZT12-15 2.0631250000000003 2.053435 2.0728150000000003 ZT16-19 1.544805 1.544805 1.544805 ZT20-23 5.13676 5.13676 5.13676