brake pad thickness

[JHZR2]

Hi,

Ill be taking my wheels off in a day or two to do a fluid flush, but looking in today, it seems to look like the rear brake pads are much thinner than the fronts. I changed all the pads at the same time, and since the rears do much less work, what gives?
Are the rear pads usually thinner then the fronts when purchased new? I did them about a year ago, and dont really recall. I used pagid pads from fastlane.

Any info on that would be really appreciated... It seems to me thta my car is making a slightly different sound now, and is slightly slower than before, so I have to wonder if the rear calipers are somehow sticking or something.

Thanks,

JMH