Complex sentence: As of 2011, the area under oil palm plantations was 7.8 million hectares, of out of which 6.1 million hectares were productive plantations under harvest and thus Indonesia has become the global leader in crude palm oil (CPO) production.
Split into simpler sentences: As of 2011, the area under oil palm plantations was 7.8 million hectares, of out of which 6.1 million hectares were productive plantations under harvest. This makes Indonesia the global leader in crude palm oil (CPO) production.