Before the oil boom brought increased tax revenue to North Dakota, the Legislature would have to issue bonds for such things as college buildings, building maintenance or special highway projects.

From 1993 to 2001, for example, the Legislature issued $51.2 million. And from 2003 through 2009, $43.7 million.

Those bonds have to be paid back.

"In the current biennium, our debt service is $13.5 million," said State Budget Director Pam Sharp.