nesting data (but with error on redraw)
filtered data to specific year on dropdown.  Have axis need rects.
Re-added in some of Bostock's grouped bar chart code but also kept Lincoln's filtering solution.  Now appears to be drawing the correct things on change.
Deleted some old commented code and added some explanatory comments on what I did to make the chart work.
Broke up the data keying function to account for extra dimensions. Created multiple variables that contain various maps of data.
Changed color range
switched order of colors. Added legend.