Grade inflation runs rampant in American colleges and universities. The average GPA at private schools — on a four-point scale — has risen from 3.09, in the 1991–2 academic year, to 3.30, in 2006–7.
Over the same period, public school GPAs inflated from 2.85 to 3.01.
Now, after five more years of progress, I can only imagine what’s average. Actually, no, I can do more than imagine; I can project with some confidence:
Over the last 50 years, GPAs have increased by roughly 0.1 to 0.2 per decade (on the high end for private schools and on the low end for public schools), a rate that is consistent with the trends over the 16 years noted in the first figure.