Agriculture refers to the production of goods through the growing of crops, animals and other life forms. The study of agriculture is known as agricultural science. As of 2006, an estimated 45 percent of the world's workers are employed in agriculture (from 42% in 1996). However, the relative significance of farming has dropped steadily since the beginning of industrialization, and in 2006 – for the first time in history – the services sector overtook agriculture as the economic sector employing the most people worldwide. Despite the fact that agriculture employs over one-third of the world's population, agricultural production accounts for less than five percent of the gross world product