The table below shows the marginal private benefits and the marginal private costs of flu shots. The marginal private benefits represent the market demand curve {DIN}, and the marginal private costs represent the market supply curve (SW). Marginal private Marginal Quantity Of flu benefits private costs ShOts Dlnternal Slnternal 1,000 $2,500 $1,800 2,000 $2,250 $1,900 3,000 $2,000 $2,000 4,000 $1,?50 $2.100 5,000 $1,500 $2,200 6,000 $1,250 $2,300 7,000 $1,000 $2,400 8,000 $750 $2,500 9,000 $500 $2,600 Suppose that getting a flu shot generates a positive externality, and the external benefit is $2,200 per thousand flu shots. Compared to the socially optimal amount of flu shots, the amount of flu shots taken at the market equilibrium is _____ shots too few