IELTS WRITING TASK 1

Please kindly take a look at my writing for task 1 IELTS. Any comments would be appreciated. Thank you so much!

"The line chart compares the differences in the percentages of 65-year-old-or-over people between USA, Sweden, and Japan from 1940 to 2040.
Overall, the proportion of elderly people in all three countries increased through the 100-year time span, although Japan had a long decrease in the first half of the period.
In 1940, Sweden and USA citizens who were 65 or above accounted for seven and nine percent of the country's population, respectively. In the next 40 years, they both increased gradually to nearly 15 percent. The Sweden elderly proportion was slightly lower than USA elderly proportion in this period. From 1980 to 2020, the proportion in USA remained at around 15% while the proportion in Sweden saw a fluctuated rise and reached nearly 20% in 2020. In the next 20-year period, the proportions are expected to reach the peaks of 25% in Sweden and 23% in USA.
Japan had a different trend compared to USA and Sweden. From 1940 to 2030, the proportion of population aged 65 years or over in Japan declined and inclined slowly from 5% in 1940 to nearly 10% in 2020. Predictively, this proportion in Japan is going to increase to 10% in 2030. In the last 10-year period, the proportion will jump quickly to about 27 percent and pass this proportion in both USA and Sweden."