condition mean min max ZT0-3 2.292145 2.226675 2.357615 ZT4-7 3.578645 3.578645 3.578645 ZT8-11 8.842935 8.842935 8.842935 ZT12-15 0 0 0 ZT16-19 8.81605 8.81605 8.81605 ZT20-23 5.01008 5.01008 5.01008