I think, like the Bill Gates haters who interpret him talking about reducing the rate of birth in Africa as wanting to kill Africans, you're interpreting it wrong.
The graph says horse ownership per person. People probably stopped buying horses, they let theirs retire (well, to be honest, probably also sent to the glue factory), and when they stopped buying new horses, horse breeding programs slowed down.
The graph says horse ownership per person. People probably stopped buying horses, they let theirs retire (well, to be honest, probably also sent to the glue factory), and when they stopped buying new horses, horse breeding programs slowed down.