This is going to be a hard one to explain. I'm tracking machines and when the were serviced. based off of that service, they get a percentage, managers then add the current average with the last average to decide if action is needed.

I need to show the last 6 services of each machine and then average each service with the last one.

Example:

Machine 1
5/5/14     $96.00 47%
5/12/14     $98.46 88%
5/20/14     $109.00 133%
5/29/14     $95.00 83%
Machine 2
...
...
...

so the average of 83% and 133%
then 133% and 88%
then 88% and 47%
etc..

I tried lots of options with no success