The film industry or motion picture industry comprises companies involved in film production, distribution, and exhibition. It includes film production companies, film studios, cinematography, screenwriting, pre-production, post-production, film festivals, and actors, directors, and other film crew. While around 400 companies are considered permanent, the number varies depending on productions. Approximately 43% are production companies, 13% are distribution, and 44% are exhibition. In 2006, the UK film industry contributed £4.3 billion to the economy, up from £3.1 billion in 2004.