AC Filter dirty ???

[Sunline1]

Ever year I clean my AC filter and there never seams to be any significant amount of dirt.

I rinse it out in the sink with water, and there doesn't seam to be much of anything come out.

Yet I will have dust on the table and counters etc, you wonder where it comes from. You would think it's in the air, therefore the AC filter would have some dust etc.

Any thoughts, comments, etc.

Sunline1