condition mean min max ZT0-3 3.4873583333333333 2.45095 4.240845 ZT4-7 1.782015 1.782015 1.782015 ZT8-11 3.5617400000000004 3.5617400000000004 3.5617400000000004 ZT12-15 3.699155 3.507365 3.8909450000000003 ZT16-19 4.4856300000000005 4.4856300000000005 4.4856300000000005 ZT20-23 5.5361899999999995 5.5361899999999995 5.5361899999999995