That represents an increase from 3.6 million to 4.3 million adults over those three years.
The Media Audit found that trends weren't quite as positive for competing national newspapers, such as USA Today, which saw total readership decline, and The New York Times, which remained flat. At USA Today, total readership in the 80+ markets tracked by The Media Audit dropped 8.3% from 2007-2009, from about 3.15 million to 2.9 million.
Some 4.4% of U.S. adults in the measured markets read The New York Times in 2009 -- representing about 6.3 million people. That's the same proportion as in 2007.
The Media Audit also found that WSJ readers were more affluent, on average, than readers of the other two newspapers: 29.6% of WSJ readers have household incomes of $150,000 or more, versus 22.5% of New York Times readers and 16% of USA Today readers.
The Media Audit findings seem to confirm a trend suggested by the most recent circulation figures from the Audit Bureau of Circulations, covering the six-month period from October 2009-March 2010.
Compared to the same period a year earlier, ABC found that total weekday circulation declined 13.6% at USA Today, to 1,826,622, while The New York Times dipped 8.5% to 951,063. The Wall Street Journal saw total weekday circulation edge up 0.5% to 2.1 million over the same time period.
These figures compare to an industry-wide drop of 8.7% in the combined circulation of 604 newspapers tracked by the ABC. Going back a bit further, USA Today's weekday circulation has declined 20% from 2,278,022 in the six-month period ending March 2007, while The New York Times has dropped 15% from 1,120,420.