There is tons of error in accuracy when using calipers...the amount of force you apply, the site (and where on the site) you take the measurement. It's systematic error written all over the place...the chart should be the least of your concerns .
But as long as you do the same shit everytime, you standardize your measurements...and can therefore track the changes, rather than the absolute values. I fucking hate my calipers, I got a Fat Track II.
And yeah, there are several BF equations that just use a different number and different sites all together. If you can find the equations and the procedures, you should be good...but again, the accuracy sucks.