I agree with the OP on this, despite not having physical numbers. Just look at the amount of devices sold, in the past 5 years. With the sales of devices that can play CDs, LPs, and Cassetts going down quite quickly, it has to be in relation to what type of media people are consuming. If people aren't buying CD players, it is likely that they aren't buying the media that is used inside those devices. 
I don't like this fact (I love my jewel cases, and LPs of even some recent music), but I think it is the unfortunate truth.
		
		
	 
Looks like physical is losing out to digital (quoted from RollingStone.com):
The 2009 year-end Nielsen SoundScan numbers reveal that Taylor Swift edged Susan Boyle in terms of album sales, and that the Beatles and Michael Jackson can still move major units. But how did the music biz do overall last year? Slightly better than the year before. Total music purchases were up 2.1 percent over 2008, as 09 brought in 1.545 billion overall music sales  which factors in albums, singles, digital tracks and music videos  compared to the 1.513 billion combined in 2008.
(Check out Rolling Stones Best Albums and Best Songs of 2009.)
Despite the two percent increase, total album sales continued to slide at an alarming rate. Physical and digital sales combined for 373.9 million albums sold in 2009, down from the 428.4 million in 2008 for a 12.7 percent decrease. The number of albums purchased via online retailers also dropped significantly, from 27.5 million in 2008 to 25.3 million in 2009, an eight percent slide. However, more consumers flocked to digital services for album purchases: the year-end figure of 76.4 million albums sold is a 16.1 percent increase over 2008s figures. It appears only CDs were affected by the album slump, as vinyl sales were also up 33 percent over 2008 figures.
The sales decline was spread across all genres: rock sales were down 11.1 percent, rap sales down 20.9 percent and Latin music down a staggering 34.3 percent. Only the country genre, which saw its total sales slump slightly from 47.6 million to 46.1 million, and jazz, whose sales only fell 0.1 percent from 2008, seemed to have bucked the trend.
The 2009 market share chart reveals some major labels are more major than others. UMG led the charge once again by selling 30.2 percent of all albums bought in 2009, down slightly from their industry-leading 31.5 percent a year ago. Thanks in large part to Michael Jackson, Sonys numbers were well up, grabbing a 28.58 percent market share compared to their 25.3 percent total in 2008. Warner Music saw its share drop from 21.38 percent in 08 to 20.55 percent in 09, while EMI made up that difference by jumping from 8.97 percent in 08 to 9.21 percent in 09. All other labels combined factored in for an 11.47 percent market share.
The best sign for the industry: Digital track sales topped the billion mark for the second consecutive year, besting 2008s record with 1,160,000,000 downloads combined. Eighty-eight songs alone topped the million-download mark in 2009, up from just 71 songs last year. Additionally, in 2008, Rihanna was the top digital draw with 9.9 million downloads. In 2009, four artists topped that: Lady Gaga, Black Eyed Peas, Michael Jackson and Taylor Swift. To make a long sales story short: Digital > CD.