How often do upper respiratory infections occur with people taking Enbrel?

I have been on enbrel now for 7 years, 50 mg twice weekly. I have noticed an increase in the frequency of upper resp infections. Usually starts with sore throat, progresses to phlegm, sinus pain and sometimes ear pain and last symptom is persistent cough for 2-3 days. Over the counter stuff eases symptoms but i have had antibiotics when it gets severe. I've noticed that i get upper resp infections (only.. my body feels fine) at least 3-4 times per year... So far, yearly blood work is good.. anyone experiencing similar symptoms while on Enbrel? thanks