According to a January 5, 2017, article in The Guardian, consumer spending in Britain on subscription streaming services for movies and TV shows grew by \(23 \%\) between 2015 and 2016 to \(£ 1.3\) billion and, for the first time, exceeded sales of DVDs and Blu-ray discs, which fell by \(17 \%\) to \(£ 0.9\) billion in 2016. If the market for physical video discs were a monopoly, how far would its demand curve have to fall before the firm exited the industry? Use a diagram to explain your answer.