Here is the breakdown for illegal immigration by country of origin:
By region:
Mexico + Central America collectively made up 68% (~9.3 million)
South America – ~12% (~1.7 million)
Asia – ~6% (~851,000)
Europe, Canada, Oceania – ~7% (~896,000)
Caribbean – ~4% (~575,000)
Africa – ~3% (~415,000)
Source: migrationpolicy.org