GM's 2015 profit came largely from its North American operations, led by U.S. demand for trucks and crossover SUVs. Profit from international sales, which includes China, edged up 15 percent to $1.4 billion. But North American profit jumped 67 percent to $11 billion. GM narrowed losses in Europe but widened them in South America. The data show just how much GM depends on U.S. demand for its high-profit-margin trucks and SUVs.