The line graph shows the percent of cars for sale at a used car lot on a given day by model year.

The x-axis represents the model years, and the y-axis represents the percentage of cars for sale.
If the total number of cars for sale in 2013 was 200, and the total number of cars for sale in 2014 was 250, what was the total number of cars from model years 2013 and 2014 combined?