pimpineasy

Look at the Y axis. Its logarithmic, not linear.
Notice how 100K is the same distance from 1 mil as 10 mil.
Based on that, we can tell that half the distance on y axis means you cover about 1 tenth of the difference in 2 points.
So the midpoint between 100,000 and 1 million is only (.10)(900000)+100000 = 190,000.
The midpoint between 190,000 and 1 million is only (.10)(810000)+190000 = 271,000
270,000 is about the 10% line in 2012, so you can only say that John Stevensen will have 271,000 with 90% confidence.
To get his target 630,000 you probably have to go to 70% or so.