I need to try to infer the best-guesstimate overall rate of appreciation per month of industrial properties in our city from mid-2006 to mid-2007. The problem is, I have only one sale which sold in 2006 and was sold again in 2007. It implies a 2.25% per month increase. Gut tells me this is about right, but I need to try to prove it.

I have a set of data. The data represents industrial properties that have sold, and then resold over the past several years.

It’s my hope that the big brains at the Dope could help me figure out how either to calculate or to graph in such a way that supports (or discredits…but hopefully supports) that the industrial market appreciated at 2.25% per month from '06 to '07. Below is the categories of sales I have, the number of sales, and the median of the properties’ monthly increase (simple, not compound).

Bought 2002 Sold 2004 – 4 sales – 1.04% / mo.

Bought 2002 Sold 2005 – 4 sales – 0.88% / mo.

Bought 2002 Sold 2006 – 4 sales – 1.53% / mo.

Bought 2002 Sold 2007 – 5 sales – 1.57% / mo.

Bought 2003 Sold 2005 – 5 sales – 2.05% / mo.

Bought 2003 Sold 2006 – 1 sale – 3.48% / mo.

Bought 2003 Sold 2007 – 3 sales – 2.08% / mo.

Bought 2004 Sold 2005 – 3 sales – 1.59% / mo.

Bought 2005 Sold 2006 – 3 sales – 2.87% / mo.

Bought 2006 Sold 2007 – 1 Sale – 2.25% / mo.

My solution doesn’t need to be mathematically incontrovertible, only a reasonable interpretation given the limited real-world data available. My gut tells me that the market was warming up in 2002-2004, the greatest increases occurred in 2005-2006, and the market had cooled down for 2006-2007.

Please Big Brains, use your powers for good and assist this poor soul. Because this thing makes me want to stab my eyes with knitting needles just so I don’t have to look at it anymore.