A breakdown of the population rate in three different counties of Oregon from 1940 to 2000 is presented in the line graph. Overall, Washington was an ideal place to live for most people. Meanwhile, Columbia and Yamhill always presented the same population growth.
Initially, more people preferred to live in Washington. Its population reached at 75 thousand and was by far the highest. For the other countries, the population numbers stood at a very similar level, around 30 thousand. However, by 2000, there had been a significant change. A gap between the figure for Washington and other countries widened out from 45 to over 150 thousand. Interestingly, Columbia's population rate had fallen back to the 1940 Washington figure. This was accounted for 75 thousand.
During the timeline, all figures experienced an upward trend. The most noticeable change was seen in the population rate of Washington. It rose significantly to just over 120 thousand in 1970 and continuously jumped over 240 in the end of the period. For Columbia and Yamhill, the population growths always had a same pattern with a less marked gap (15 thousand in 2000).