I was astounded to discover the following facts at Migration Information Source:
“The Immigration Act of 1990 established the Diversity Visa Lottery (also known as the green card lottery) to allow entry to immigrants from countries with low rates of immigration to the United States. The act states that no more than 55,000 diversity visas are made available each fiscal year. Of the 55,000 visas, 5,000 have to be used for applicants under the Nicaraguan Adjustment and Central American Relief Act of 1997, thus reducing the available number to 50,000.
Applicants registered for the 2010 lottery (run between October 2 and December 1, 2008) were selected at random from over 13.6 million qualified entries. The number of qualified entries totaled 5.5 million in the 2007 lottery, 6.4 million in the 2008 lottery, and 9.1 million in the 2009 lottery. (The Department of State does not release the total number of applications received, only the number of qualified entries.)”
So the odds of getting a green card visa were roughly 272 to 1 in 2010. It is interesting that the number of qualified entries increased each year between 2007 and 2010.