The line graph illustrates the changes of population in three counties, including Columbia, Yamhil, and Washington in the United States of Oregon from 1940 to 2000. The unit is in thousands.
Overall, it is readily apparent that population in Washington was greatest throughout the period, while Yamhil and Columbia had nearly the same number but Columbia was slighly fewer .
In 1940, the population of Washington was 75,000 which was 2.5 times higher than the number of Yamhill county, followed by Columbia which was slightly lower than Yamhil 5,000.
In addition, in the next 30 years, Washington people significantly rose to approximately 120,000, while Yamhil and Columbia increased 15,000 and 10,000, respectively.
Looking at the year 2000, the population of Washington surged to 240,000, the highest among the period. Additionally, the trend of Yamhil and Columbia was the same, doubling from the year 1970 which was 75,000 and 60,000, respectively.
