MS SQL: Calculating run down dates from only percentages
===

I have a table with information on resources, basics are:

    ID    Total    Start        End          Used
    ----------------------------------------------
    1     350      01-01-2012   31-12-2012   80.6%
    2     250      01-01-2012   31-12-2012   51.5%
    3     3500     01-01-2012   31-07-2013   12.5%
    4     350      01-01-2012   31-10-2012   91.0%

Columns are:
    Total -- Total number of the resource (Being currency, time, paper etc).
    Start -- Start date of resource
    End -- End date of resource
    Used -- Percentage of the resource used to date

I have to try to work out (or estimate) when the resource will run out at the rate used so far.
I've tried several different ways using the percentage used and the percentage but nothing makes sense, I'm pretty sure there's a simple way to do this that's staring me in the face but I can't find it.

My ideal output would be in text below but I will probably format in the application:

    You have used X% of your [resource name] in Y% of the time allotted, 
    at this rate the resource will run down around [Run Down Date].

Can anyone work out how this can be calculated?

[SQL Fiddle to play with][1]


  [1]: http://www.sqlfiddle.com/#!3/2b212/1