Forbes is out with its annual assessment of the value of National Football League teams, and, no surprise, the numbers are way up from a year ago.

"The $1.43 billion average is 23 percent more than a year ago, the biggest year-over-year increase since 1999," writes Mike Ozanian, who also mentioned this interesting tidbit:

"The hefty premium paid by Steve Ballmer for the [Los Angeles] Clippers has definitely gotten the attention of the NFL, with several owners telling me there will likely be an announcement within two years of two NFL teams moving to Los Angeles and sharing a new stadium."

Despite difficulties making the playoffs in recent years, the Dallas Cowboys have had no trouble becoming the most valuable franchise in American sports, nearly doubling from $1.65 billion in 2009 to $3.2 billion this year, according to Forbes.

The NFC East clearly is the dominant division, financially, with the Washington Redskins third at $2.2 billion, the New York Giants fourth at $2.1 billion, and the Philadelphia Eagles seventh at $1.75 billion.

No. 2 overall was the New England Patriots, with a value of $2.6 billion (also higher than the top baseball franchise, the New York Yankees). Other top NFL franchises: the Houston Texans (No. 5, 1.85 billion) and the New York Jets (No. 6, $1.8 billion).

All of these NFL teams saw their valuations, based on revenues, soar by 28 percent or more from the previous year.

The Eagles, up from $1.3 billion in 2013, finished No. 7 for the seventh straight year. The franchise first passed the $1 billion mark in 2006, when it was ranked No. 4. It was No. 5 in 2006 and 2007.

Many observers thought owner Jeffrey Lurie grossly overpaid for the Eagles in 1994 when he bought the club from Norman Braman for about $195 million.

That's a total increase of about 772 percent over 20 years.

Even the least valuable NFL franchises are now worth almost $1 billion. The Buffalo Bills' value was put at $935 million, the St. Louis Rams at $930 million.

Contact staff writer Peter Mucha at 215-854-4342 or Follow @petemucha on Twitter.