Why is the Australian dollar so low, when it's the U.S who have the screwed econonmy?

I understand global markets, but Australia is at an all time low of unemployment, we're all working, shopping, not a very credit driven society yet. But I look at it time and again and it still makes no sense that the AU dollar drops, start of the year it was 96c now it's like back in the 80's, shouldn't it be the U.S dollar that drops for a change? they're the ones who have stuffed up. Australias economy should be blitzing the U.S dollar by now. It just not making sense at all.