Learn English – Better half of the decade

A decade means a time period of 10 years. You could say something like:

I quit that job last decade.

Now this is 2016, you actually quit the job in 2009. Technically it was just 7 years ago. But you can still say it that way. But you cannot refer '2003-2010' as a decade because that's only 7 years. However, say you were a vegetarian and you quit meat in 2003 and that went on till 2010. Now, you could say that:

I was a vegetarian last decade.

That doesn't mean you were a vegetarian for 10 years. So that is okay. But you cannot refer 7 years as a decade. Hope this helped.

In this particular example, 'than before' is a shortened form of 'than they were before.'

NOTE: The example statement tells nothing about what the other half thinks. Some of the other half may well have no opinion and assumptions about what they think are invalid.