My monocyte percentage has been a little elevated and persistent the past year ( aug 2021: 12.4, february 2022: 15.3, october 2022: 15.8). the latest result is absolute monocyte 0.6 and percentage monocyte 15.8. what are possible causes?

You don't mention the results of the rest of your cbc& differential cell count. When your monocytes in the peripheral blood exceeds 10% it indicates that your body is reacting to something. It could be to infection such as mononucleosis, autoimmune disorder,certain medications or be a sign of a bone marrow disorder. A hematologist is best to evaluate & advise you. Appropriate testing will be done