The first graph is a compound bar chart of my milegae for the year, showing the distance each month I have ridden on and off road. The graphs that sportstracks produces just show mileage for the month. But it is interesting to see how much of that mileage is on-road and how much is off road.
The second graph is a Pie-Chart showing the percentage of time spent on and off road. I thought that looking at time rather than distance made sense as you obviously cover more distance in less time on-road. At the moment I have spent slightly more time on-road than off-road. The ideal split would probably be 50/50.