<Ul> <Li> Grandparent rule . Section 322 of the INA, added in 1994, enabled children of a U.S. citizen who did not get citizenship at birth, to use the physical presence period in the U.S. of a grandparent who was a citizen to qualify for U.S. citizenship . In 2006, there were 4,000 applications of citizenship using the physical presence of grandparents . Israelis comprise 90% of those taking advantage of the clause . </Li> </Ul> <Li> Grandparent rule . Section 322 of the INA, added in 1994, enabled children of a U.S. citizen who did not get citizenship at birth, to use the physical presence period in the U.S. of a grandparent who was a citizen to qualify for U.S. citizenship . In 2006, there were 4,000 applications of citizenship using the physical presence of grandparents . Israelis comprise 90% of those taking advantage of the clause . </Li> <P> According to a senior fellow at the Migration Policy Institute, "citizenship is a very, very valuable commodity". However, one study suggested legal residents eligible for citizenship, but who don't apply, tend to have low incomes (41 percent), do not speak English well (60 percent), or have low levels of education (25 percent). There is strong demand for citizenship based on the number of applications filed . From 1920 to 1940, the number of immigrants to the United States who became citizens numbered about 200,000 each year; there was a spike after World War II, and then the level reduced to about 150,000 per year until resuming to the 200,000 level beginning about 1980 . In the mid-1990s to 2009, the levels rose to about 500,000 per year with considerable variation . In 1996, more than one million people became citizens through naturalization . In 1997, there were 1.41 million applications filed; in 2006, 1.38 million . The number of naturalized citizens in the United States rose from 6.5 million in the mid-1990s to 11 million in 2002 . By 2003, the pool of immigrants eligible to become naturalized citizens was 8 million, and of these, 2.7 million lived in California . In 2003, the number of new citizens from naturalization was 463,204 . In 2007, the number was 702,589 . In 2007, 1.38 million people applied for citizenship creating a backlog . In 2008, applications decreased to 525,786 . </P> <P> Naturalization fees were $60 in 1989; $90 in 1991; $95 in 1994; $225 in 1999; $260 in 2002; $320 in 2003; $330 in 2005 . In 2007 application fees were increased from $330 to $595 and an additional $80 computerized fingerprinting fee was added . The biometrics fee was increased to $85 in 2010 . On December 23, 2016, the application fees were increased again from $595 to $640 . The high fees have been criticized as putting up one more wall to citizenship . Increases in fees for citizenship have drawn criticism . Doris Meissner, a senior fellow at the Migration Policy Institute and former Immigration and Naturalization Service Commissioner, doubted that fee increases deter citizenship - seekers . In 2009, the number of immigrants applying for citizenship plunged 62 percent; reasons cited were the slowing economy and the cost of naturalization . </P>

Which of the following is generally considered the most important act of citizenship for an american