36 million
The estimated number of potential trick-or-treaters in 2009 — children 5 to 13 — across the United States. This number is up about 190,000 from a year earlier. Of course, many other children — older than 13, and younger than 5 — also go trick-or-treating.
Source: 2009 population estimates <http://www.census.gov/newsroom/releases/archives/population/cb10-81.html>.
111.3 million
Number of occupied housing units across the nation in 2009 — all potential stops for trick-or-treaters. Source: Housing Vacancies and Homeownership <http://www.census.gov/hhes/www/housing/hvs/historic/>.
92%
Percentage of households with residents who consider their neighborhood safe. In addition, 78 percent said there was no place within a mile of their homes where they would be afraid to walk alone at night. Source: Extended Measures of Well-Being: Living Conditions in the United States, 2005
<http://www.census.gov/population/www/socdemo/extended-05.html> Table 4.

