You have asked this question before. The reason is that the default template uses my Garava font, which has those values.
However, I don’t see these same values in FontCreator 6.0 Are you still using version 5.6?
What I see now is 1716 and -418.
Anyway it makes no difference. You need to modify them to suit the current font in any case by using Calculate on the Metrics tab when you have designed your font.