Carlisle has one of the higher price points in the area, so there is a smaller buyer pool in general.
In 2005, the average sales price in Carlisle was $955,383 and the median sales price was $800,000. In 2014, the average sales price was $924,646 and the median sales price was $804,500. 2015 data is not complete yet, but is trending slightly below 2014. While that not may look like much of an increase, that is up from 2011 when the average sales price was $733,675 and the median sales price was $614,750.
Since Carlisle is at one of the higher price points and there is less inventory than other towns, the statistics can be impacted by sales on the low and/or high end.
If you want details by year feel free to reach out to me.