Thats very dependant on how high of a quality your individual parts are...
Usually a voltage change is what starts reducing the lifespan of any particular item, the time of life is not really anything predictable, as some parts are slightly higher/lower quality.. its all a luck of the draw, such as with GPU's and CPU's and RAM.
In terms of making a chart, it really is fairly impossible to get a really averaged out detailed chart. The best bet to picture it as.. the more volts you pump into the particular overclock, the higher stats it has to burn out. Time is very relative to one major thing, being able to remove the excess heat from the overclocked/voltaged item.