condition mean min max ZT0-3 1.2021566666666668 1.2021566666666668 1.2021566666666668 ZT4-7 1.6803949999999999 1.6803949999999999 1.6803949999999999 ZT8-11 0.94974 0.94974 0.94974 ZT12-15 2.020645 2.020645 2.020645 ZT16-19 4.82095 4.82095 4.82095 ZT20-23 1.0176334519999999 1.0176334519999999 1.0176334519999999