Per capita production of milk = \(\frac{\text{Milk production (gallons in millions)}}{\text{Total population (millions)}}\)
From the graph:
- 1990: Milk ≈ 7, Population ≈ 33+34=67 → ratio ≈ 0.104
- 1991: ratio slightly higher
- 1992: Milk ≈ 7, Population ≈ 35+36=71 → ratio ≈ 0.098 (lowest)
- Later years have higher ratios.
Thus, the least per capita milk production occurred in 1992.