The New York Yankees are now worth $3.7 billion.

So says Forbes, which has been publishing the list of most valuable Major League Baseball franchises for 20 years. In each year, the Yankees have been worth the most money, this time being almost $1 billion more than the next most valuable team, the Los Angeles Dodgers ($2.75 billion).

The magazine says the average MLB team is now worth $1.54 billion, 19 percent higher than just a year ago. Greatly contributing to the higher values is MLB Advanced Media, the league's digital and technology arm which has experienced huge growth in recent years and is equally owned by the league's teams.

Rounding out the top five most valuable are the Boston Red Sox ($2.7 billion), the Chicago Cubs ($2.675 billion) and the San Francisco Giants ($2.65 billion).

The Ricketts family has invested in Wrigley Field and the surrounding neighborhood. AP Photo/Andrew A. Nelles

The five most valuable teams have won six of the last eight World Series. The defending champion Cubs have seen their value skyrocket in recent years.

When the Ricketts family bought the team and a piece of the local sports network for $845 million in 2009, a record for an MLB franchise, many thought the price was insanely high, especially in the midst of the economic downturn.

But in the past seven seasons, Forbes projects the value of the Cubs as having increased by more than 180 percent, factoring for inflation.

With little help from the city, the Ricketts family has put much of those gains back into the ballpark, buying buildings with rooftops overlooking the park as well as through its Hickory Street Capital Partners real estate investment firm, rebuilding part of Wrigleyville. A new plaza, called the Park at Wrigley, adjacent to the stadium, opened Monday.

"We always talked about it in the strategic plan that the business side and the baseball side would come together," Tom Ricketts told ESPN.com on Monday. "We're just really fortunate that, pretty much, all the right moves were made to make that happen. Everything we're doing off the field, everything we're doing on the field, everything we're doing to the field [has] all kind of come together."

The Steinbrenner family has owned the Yankees since 1973, longer than any other current baseball ownership group. The group organized by George Steinbrenner paid $10 million for the team, buying it from CBS, which sold the Yankees for $3.2 million less than it paid.

Factoring for inflation, the Yankees' value has increased 6,627 percent since Steinbrenner purchased it.