Of the 5.4 deaths per billion passenger-miles, are there any statistics to show what percentage of these are the result or have a contributing factor of cars in

Of the 5.4 deaths per billion passenger-miles, are there any statistics to show what percentage of these are the result or have a contributing factor of cars involved? It would be fascinating to see if the 5.4 statistic would drop significantly if the car-related deaths were factored out.