The increase in the cost of Groucho glasses from 2009 to 2011 was 60% (from $15/dozen to $24/dozen), according to the 2011 Cost of Laughing Index – an annual report of the fluctuations in the finances of chuckling consumers. The index looks at the price changes of 16 different comedy-based things from comedy club tickets to rubber chickens. Overall for 2011 the cost of laughter is estimated to be up 3%.

Related Fact: Apparently the air has really been let out of the Whoopie Cushion market (I’m so sorry for that joke). Just last year, a dozen of the Bronx Cheer-emitting devices rang in at around $3. Today, they can be had for right around $1.20.

[Sources: AOL Weird News. See previous Numbers of the Day here.]