on the average
Typically; in general. How many cupcakes does your shop sell daily, on the average? I know he has had some awkward moments, but, on the average, Tim is a nice guy.
on the average
and on averagegenerally; usually. On the average, you can expect about a 10 percent failure rate. This report looks OK, on average.
on the average
As a rule, usually, as in On the average, about 15 percent of the freshmen class will drop out before graduation. This expression uses average in the sense of "a norm or standard." [First half of 1700s]