It is an interesting graphic. I think they left a few things off of significance though. While they have the air bag start date, I think it fails to take into account the dramatic increase in then other interior design mechanism (knee bags, side-impact bags, two stage bags, etc.
Also, and from an ER doc point of view I think this is key, over the past several years we've seen those cable fences along divided interstates and 4 lane highways. I'm convinced those things have had a HUGE impact on reducing vehicular fatalities by reducing the head-on collisions of vehicles that crossed the divider at high speed into oncoming high speed traffic--particularly big rigs.