I Have Recently Had 4 Checks On Platelets Which Show

I have recently had 4 checks on platelets which show 2 as clumping with no read and 2 at 84 and the last one as 98 corrected thru light blue top results corrected for effects of dilution.
My medications are only simvastatin and previcid. I am 80 and in excellent health other than this annoyance of low platelet count. Last year my count was 164.
Can you offer an explanation?
Thanks
Ralph