By the Numbers: The Bush Family By Amy Roberts, CNN Library March 8, 2013 -- Updated 1855 GMT (0255 HKT) 6 - Number of children George and Barbara Bush had 3 - Living members of the Bush family who graduated from Yale University. 4 - Trips to Iraq while in office by President George W. Bush after the war began. (CNN) -- Former President George H.W. Bush released an updated version of his book, "All the Best, George Bush; My Life in Letters and Other Writings," in which he talks about how he had to keep himself in check while his son George W. Bush faced criticism while in the White House. "My heart went out to him," the 41st president wrote of the 43rd. At the same time Jeb Bush, a former two-term Florida governor and possible 2016 presidential candidate, also released the book he co-wrote on the immigration debate, "Immigration Wars." Here's a look at the Bush family, by the numbers: 2: Presidents whose sons later became president: John Adams and John Quincy Adams, and George H. W. Bush and George W. Bush. 444: The estimated number of people in the United States named George Bush, according to the How Many of Me.com website. 3: Members of the immediate Bush family named George. In addition to George H.W. and George W., George P. is Jeb Bush's son and a managing partner of an investment firm in Fort Worth, Texas. 6: Number of children George H.W. and Barbara Bush had: George W., Robin, Jeb, Neil, Marvin and Doro. Robin died of leukemia as a child in 1953. 17: Number of the Bushes' grandchildren. 3: Living members of the Bush family who graduated from Yale University -- George H. W. ('48), George W. ('68), and George W.'s daughter Barbara ('04). 2: Times brothers George W. and Jeb Bush were each elected governor. George W. Bush was governor of Texas from 1995 to 2000 and Jeb Bush was governor of Florida from 1999 to 2007. 65: Percentage point drop from George W. Bush's highest presidential job approval weekly rating (90%) in 2001 to his lowest (25%), which was recorded three times in Gallup's weekly poll in October and November 2008. 60: Difference in George H. W. Bush's highest and lowest job approval ratings: 89% in February 1991 and 29% in July 1992. 60: Types of endangered species whose habitats were saved during the Florida state program to clean up the Everglades, which was launched while Jeb Bush was governor. 12: Age of George W. Bush's Scottish terrier, Barney, who died from lymphoma in February 2013. While he was "first dog," Barney appeared regularly in online videos made by the White House Communications Agency. 4: Trips to Iraq while in office by George W. Bush after the war there began in 2003 3: Strands in former first lady Barbara Bush's trademark pearl necklace. 48-3: Score in the most recent football game (September 2012) between Texas A&M University, site of the George Bush Presidential Library and Museum, and Southern Methodist University, where the George W. Bush Presidential Library and Museum will open to the public on May 1.