The manager of a bank recorded the amount of time each customer spent waiting in line during peak business hours one Monday. The frequency table below summarizes the results.

WaitingTime (minutes)	Numberof Customers
0-3	11
4-7	13
8-11	13
12-15	8
16-19	6
20-23	2
24-27	1

If we randomly select one of the times represented in the table, what is the probability that it is at least 12 minutes or between 8 and 15 minutes?