In Australia about 15% of wage earners earn minimum wage, nearly triple the US rate. I wonder if some higher-skilled minimum and near-minimum wage workers are paid less in order to subsidize the pay of the less-skilled minimum wage workers?
I strongly suspect you cherry picked stats, and I will check them more thoroughly. This one, however, is completely inaccurate. Firstly, it's a guesstimate. Secondly it deals with wages only. You did realise a great many Australians are on salary, not wages, didn't you?
But to your other point, if only 5% of US workers are on the minimum wage (and I will check), what's the problem with raising it?