The remaining funding comes from the private sector (e.g. tuition fees).
Comparing the US with Germany, for example, the US spends 0.9% of GDP from public funds and 1.6% of GDP privately for a total of 2.5% of GDP, resulting in 44% of the population being tertiary graduates.
Germany spends 1.1% of GDP from public funds and 0.2% of GDP privately, for a total of 1.3% of GDP, and 27% of its population are tertiary graduates.
So as a proportion of GDP, Germany pays only about half of what the US does, but still manages to have three fifths as many graduates as the US, proportionally. That is better value for money spent overall.
