Westcoastmom is right about the percentiles.

In a normal distribution, you'd expect 68% to fall within one s.d. (standard deviation) of average (100). Since these tests are designed to have s.d. of 15, only 16% of the population scores below 85 and only 16% scores above 115 - on each individual subtest. If 85 = 16th percentile, it makes sense that 94 = 34th.

But get the birth date fixed before you worry about an average subtest score. besides, processing speed isn't a g-loaded scale.