You should change your tires ASAP.How many miles are people getting out of their tires? I feel like mine are past the age of safety but they have plenty of meat left. I am about a day trip away from 10,000 miles. I have the OEM BT-023s and my bike is an 06 (!!!).
My mileage depends on the number of track days I attend and it is balanced by the non-existent friction levels of the greek roads.
I don't keep tires fitted for more than two years. After that period of time all their positive attributes are diminished and safety levels are diminishing too.
So make yourself a favor and put on a new set.