Interest exemption granted in PhD study period

A few days back I got the reply on my application to Statens lånekasse for utdanning, the Norwegian governmental bank for education, to be granted exempt from interest on my student loan for the period covered by my PhD studies (2007-2011). The answer was positive, though the exempt could only be granted for 3 of the 4 years due to a maximum quota of 10 years of interest exemption altogether. My student loan debt now amounts to some 27.000 Euro, after the about 4.000 Euro in interest exemption has been subtracted from the loan.