Record for most ballerinas en pointe in one place for at least a minute:

230
On Aug. 2, 2010, 230 ballet dancers in New York's Central Park completed a simultaneous en pointe for a minute, breaking the previous record of 220 en pointe dancers set in April 2009 at City Center in New York.
Source: New York Daily News, 8/3/2010

 
   
  Percentage of Americans aged 18-35 who attended a ballet performance in 2002:

3.1%
Compared to 5% in 1992.
Source: National Endowment of the Arts, 11/25/2006