condition mean min max ZT0-3 2.0873725 1.90056 2.274185 ZT4-7 2.761295 2.761295 2.761295 ZT8-11 3.1722 3.1722 3.1722 ZT12-15 0 0 0 ZT16-19 2.875515 2.875515 2.875515 ZT20-23 2.02112 2.02112 2.02112