Toyota Sells 2 Millionth Prius; Americans Still Buy Trucks

After hearing Toyota's announcement that the company had sold 2 million Prius hybrids since 1997, Jalopnik decided to put the numbers into perspective. The blog published the following graphic:

The take-away is that the American market for trucks is still vastly bigger than the global market for the Prius.

That's not shocking. People who work in construction don't stop needing trucks simply because a fuel efficient coupe appears on the market, and the American appetite for trucks is traditionally voracious. But why not compare Prius sales to a specific truck, or compare all hybrid sales to all truck sales?