That's an average, so 1/2 are waiting longer than 45 minutes.
[PEDANT MODE] No, that's not what "average" implies. The average tells you nothing about how many are above and below it. It could be that almost everybody waits 44 minutes, and one poor sucker (probably me) waits 3 weeks.
Remember, nearly everyone has more than the average number of legs. [/PEDANT MODE]