In 1900, the most popular vehicles in order were 1) steam powered, 2) electric powered, and 3) gasoline powered. Peaking in the 1910s, electric vehicle sales began to decline. Cheap petroleum, the invention of the self starter for internal combustion engines (ICEs), and the success of the Model T made this transition to ICE vehicles. Before Henry Ford introduced the moving assembly line for the Model T the average worker could not afford an automobile. The average annual wage in 1914 was $627. The Model T eventually sold for as low as $260. By the 1920s, half the cars in the world were Model T Fords powered by ICEs. Electric vehicles could not compete with the price of ICE vehicles. It took many years for interest in electric vehicles to grow once again.