Creating a Resource Allocation chart for dashboards?

Hi everyone, I've been struggling with this for a while and hopefully someone can help. I'm working to develop a variety of charts for a dashboard and one request was to create a chart showing resource allocation over time. I know I can see this chart under Project Usage on the Activities, screen, but they're looking for an equivalent graph for the dashboard. Here's an example of the chart I'm trying to create:

Issues I've run into:

• I want to show resource data over time, but the Resource Assignments chart subject does not allow me to show trending from the project's start - only the real life time since the project has been added to the database. This project was developed in another program, and I want to see the resource units for each month of the project's timeline - rather than the 'real world time'.