How to get monthly kWh usage when bill data spans months?

Hi.
In the attached sheet, I have logged my gas energy consumption (kWh) from 2006 to 2012. I want to analyse my relative consumption over time, on a monthly basis.

However, the bills have been generated by different suppliers for irregular periods (eg. 10-May-2006 to 24-Jul-2006, or 23-Feb-2010 to 6-Mar-2010). So, how can I re-tool my sheet to arrive at rough figures that can be allocated against each month?

Or, if there is no dependability about that method, do you have better suggestions for formulae which allow for effective comparison over time? Let's say, daily?

Thank-you.

Hi Andrew,

Not sure if this is what your after - please see attached.

Regards

peterrc

Originally Posted by peterrc

Hi Andrew,

Not sure if this is what your after - please see attached.

Regards

peterrc

Thanks Peter.

In fact, rather than cost and the majority of the figures you see there, what I am aiming for is this...
- I have copious entries for kWh used/consumed (let's say, from Apr 3 to July 21).
- But those periods are so irregular that they can't be compared from year to year.
- So I want to produce figures for the kWh consumption on a calendar basis. I want to see: I consumed X kWh in March 2009, X kWh in March 2010, x kWh in March 2011. Or, perhaps rather, (average?) kWh per day.

PS. Price will naturally increase; that's beyond our control as energy customers. The only controllable is usage.

Confused!