I don't know the official figures, but I do know it's less. While kinda similar sports in nature, the tackling, speed and style of play is very different. It's not just the helmets, its whole American football uniform. Pads allow for playing with pure abandon - like they did before the modern helmet and facemask came along. It's like boxing. Bare knuckle or gloved. Prize fighters won't and don't throw full force bare knuckle punches (if they value the bones in their hands) whereas Mike Tyson with gloves on literally stole many dude's souls.

In 1905, 19 football NFL players died on the field.