Which president served 4 years on office

Almost all of the presidents have served 4 years in office only a few have not such as Roosevelt who served more than 4 or the ones that either got shot or were kicked out

Of the individuals elected as president, four (William Henry Harrison, Zachary Taylor, Warren G. Harding, and Franklin D. Roosevelt) died in office of natural causes, four (Abraham Lincoln, James A. Garfield, William McKinley, and John F. Kennedy) were assassinated, and one (Richard Nixon) resigned.