Safeties are the least common method of scoring in American football but are not rare occurrences – since 1932, a safety has occurred once every 14.31 games in the National Football League (NFL), or about once a week under current scheduling rules. A much rarer occurrence is the one-point safety, which can be scored by the offense on an extra point or two-point conversion attempt; those have occurred at least twice in NCAA Division I football since 1996, most recently at the 2013 Fiesta Bowl. No conversion safeties have occurred since at least 1940 in the NFL. A conversion safety by the defense is also possible, though highly unlikely; although this has never occurred, it is the only possible way a team could finish with a single point in an American football game.