A graph plots price versus quantity of health care. A rising line labeled S and a falling line labeled D are graphed.The horizontal axis is labeled quantity of health care. It ranges from $0$ to $600$ in increments of $100.$ The vertical axis is labeled price. It ranges from $0$ to $100$ dollars in increments of $20.$ A rising line labeled S begins at the bottom left, passes through f $(150,40),$ e $(300,60),$ d $(450,80),$ a $(600,100),$ and ends at the top$-$right. A falling line labeled D begins at $(0,100$ dollars$),$ passes through g $(150,80),$ e $(300,60),$ c $(450,40),$ b $(600,20),$ and ends at the bottom right.

Refer to the graph of a hypothetical market for health care. The efficiency loss caused by the provision of health insurance covering four$-$fifths of the cost is