And that's seven and a half seconds of prosperity that you've gained since 1950, as it were, because that's seven and a half seconds in which you can do something else, or you can acquire another good or service.
你得多付出7秒半的工作时间。 换言之，1950年以来， 7秒半钟的时间，你可以做别的一些事。 或者你可以换取别的产品或服务。