Export Vendors and Customers

[Roelof Pos]

Dear All,
I've setup GNUCash for a business. I still couldn't figure out how to do
the year end. If I Export the accounts, I loose all my billing
information (Vendors, Customers). Is it possible to Export/Import that
information as well? I don't want to reenter the vendors and customers
each year.
I've read about zeroing out the accounts, but also read it has some
drawbacks.

Hope someone can help me, 
Roelof