There has been very few times the country has been in surplus. There is no doubt that Howard got us into surplus on the back of the mining boom and sales of assets. It's not something to be proud of, there should've been a much bigger surplus than $20 billion.
The fact is that Wayne Swan didn't have the revenue that Costello had.
The Australian dollar averaged 68c under Howard and 93c under Rudd/Gillard.
Over $40billion of the $96billion of debt that Costello inherited was from the Fraser years. Between 1996 and 2007, Howard sold government assets worth $72 billion with more to spare creating the surplus. When Hawke got elected the country was in recession and the budget was a mess.
Australia maintained quarterly economic growth and AAA credit rating under Rudd/Gillard. That didn't happen by chance.