This is 100% false. Perhaps you are thinking about the oft-cited statistic regarding wolves? There are literally hundreds of documented black bear attacks in the past 50 years. Pick up a copy of "Bears" by Ben East, "Bear Attacks, Their Causes and Avoidance" by Stephen Herrero, or any of the series of books by Larry Kaniut. They all document many, many attacks.

It is true that the probability of attack is remote, but it is not fewer than 10 per century. In fact, there are states that experience more than that in any given year.