nikon sales figures

How many people in the United States have digital cameras (or bought them in 2006)?

I try to know about how many people in the U.S. have digital cameras, especially video cameras. Nikon / Canon annual reports do not seem out sales made to customers U.S. (They are pooling the sales figures of all countries), so I wonder if other sources could have this information. Thanks!

According to an interesting article: Regardless, 2006 will be another year of growth for digital equipment sales, though analysts differ in rate. According to the NPD Group, sales of cameras (including digital SLRs) will reach 29.5 million units in 2006 against the 25.2 million sold in 2005. The Photo Marketing Association (PMA) is less optimistic, predicting a digital SLR camera sales to 20.7 million its estimate of 20.5 million units sold in 2005. Finally, IDC, which tracks aircraft deliveries to retailers, predicts the market to reach 31 million units.