Create a pivot widget of RSUM( [Total Quantity] ) over time (rows) and break by (columns) age range.
Scanning down each column, over rows, the numbers only increase. Now change it to a line widget....
Images lost during community platform updates...
Image of Break By setting showing the default Rows option selected.
Very busy image showing a Pivot widget with Running Sum columns vs a Running Sum row. Followed by Line widgets showing how the two Break By options manifest.
Defaulting to Columns aligns with what users expect.