Scatterplot with background area plot
 

Im plotting monthly crime data from 1960-2007 (576 data points) for USA
counties. The crime rate is the crime count divided by the population.
However, not every agency in a county reports every month, and in some cases
they dont report for a number of years.
My plots, therefore, show four lines: total pop (black), reported pop
(green, semitransparent), and crime count x 100 (blue) are all on an
adjustable vertical axis, because counties vary considerably in population
and crime counts. The fourth plot, crime rate (crime count divided by
reported pop, orange), is on a fixed axis, so different counties rates can
be compared. Ive uploaded two figures; theyre at
sociology.osu.edu/mdm/CountyPlots.pdf
To make these plots more readable, Id like to plot the green line as a
solid area in the background. Ive tried to use the €œarea€� chart type for
that plot, but it plots the data as running from 1 to 576, instead of from
20454 (1/1/60) to 37985 (12/31/07). How can I accomplish this, and in
addition how can I make this plot stay in the background?
TIA,
Mike