Complex sentence: There were 925 million undernourished people in the world in 2010, an increase of 80 million since 1990, although the increase in world population means these numbers also reflect a 2.5% drop in the percentage of undernourished people.
Split into simpler sentences: There were 925 million undernourished people in the world in 2010. This is an increase of 80 million people since 1990 or a 2.5% drop in the percentage of undernourished people.