He's 8 as of S5E4 The Beautiful Day in the Neighborhood.
Booth Tarkington died on May 19, 1946 at the age of 76.
Bramwell Booth died on June 16, 1929 at the age of 73.
Herbert Booth died on September 25, 1926 at the age of 64.
Wayne Booth died on October 10, 2005 at the age of 84.
Evangeline Booth died on July 17, 1950 at the age of 84.
Marie Booth died on January 5, 1937 at the age of 72.
Kate Booth died on May 9, 1955 at the age of 96.
Ballington Booth died on October 5, 1940 at the age of 83.
William Booth died on August 20, 1912 at the age of 83.
Henry Booth died on January 2, 1694 at the age of 42.
Margaret Booth died on October 28, 2002 at the age of 104.
Booth Tarkington died on May 19, 1946 at the age of 76.