The graph illustrates how the population in Columbia, Yamhill, and Washington changed from 1940 to 2000.
Overall, all the regions witnessed increases in their populations over the period. Moreover, Washington showed the highest population, while Columbia saw the lowest between 1940 and 2000 in comparison.
Looking at the graph in more detail, in 1940, the population of Washington was the highest in comparison to the other regions, with about 75,000. From 1940 to 1970, Washington saw a gradual growth before increasing considerably in the last thirty years and stood at just over 240,000. It still showed the greatest population in the three counties.
Taking Yamhill into consideration, its population was 30,000 at the beginning and experienced a slight rise to about 45,000 in 1970. After that, Yamhill witnessed a moderate increase and ended at roughly 90,000. Additionally, Columbia had a similar trend to Yamhill. In 1940, its figure was nearly 30,000 and by 2000, it had reached approximately 80,000, which was the lowest among the three areas.
