In the worst quarter in modern history for American newspapers, advertising sales fell by an unprecedented 28.3% in the first three months of 2009, plunging sales by more than $2.6 billion from the prior year.Statistics posted without publicity on the website of the Newspaper Association of America show that print ad sales fell by a historic 29.7% to $5.9 billion in the first period of this year and that online sales fell a record 13.4% to $696.3 million.The worst percentage decline was in the highly profitable classified advertising category. which dived 42.3% to produce slightly less than $1.5 billion in sales.As illustrated in the graph below, newspaper sales have dropped at a steadily accelerating rate since April, 2006. In records published by the NAA that date to 1950, there is no precedent for the sort of decline suffered in the first three months of this year.The $2.6 billion sales decline in the first period of this year is equal to almost a third of the $7.5 billion that newspaper ad revenues fell in all of 2008. Newspaper ad sales last year fell 16.6% to $37.8 billion, making it by far the worst 12 months in the history of the industry.Barring a miraculous turnaround in the economy, the first quarter sales performance suggests the industry could be headed to its first year since 1987 of less than $30 billion in annual sales.By contrast, newspapers sold an all-time high of $49.4 billion in advertising as recently as 2005. If the industry achieved only $30 billion in sales this year, its volume would be 40% lower than it was four years ago.The rout in the first quarter of 2009 was wide and deep, owing in part to the most difficult economy since World War II but also to major secular changes in consumer and advertiser behavior. Here is a category-by-category breakdown::: Employment classified advertising skidded 67.4% to $205.4 million.:: Real estate classified advertising slumped 45.6% to $336.9 million.:: Automotive classified advertising swooned 43.4% to $332.8 million.:: National advertising slipped 25.9% to $1.1 billion.:: Retail advertising stumbled 23.7% to $3.3 billion.:: Other classified advertising slid 16.5% to $587.7 million.