The Yankees are averaging 39,977 tickets sold per game this season, down 8.6% from last year.
Things are worse if we look at the declining trend.
What was once a stadium that was routinely full, sellouts are now rare. This season, there have only been two games with an attendance greater than 48,000 (capacity is 50,291)
And the numbers are unlikely to improve. The Yankees are 7.0 games behind the Rangers in the Wild Card race and will probably not make the playoffs. Here is how Yankees attendance has changed over the last 30 years...
Data via Baseball-Reference.com