Please review my ielts task 1 essay

My essay:

The bar chart plots the proportion of citizens in four different countries, India, china japan and the USA, in the global population. Data are shown for two years in the past, 1950 and 2000, as well as a forecast for 2050.

Overall, China had the largest share of the four; the forecast is for it to be surpassed by India, which has a stepwise increase every 50 years. The USA is consistently the third place and Japan the fourth for both actual and projected data.

Overall, these three countries made up the majority of the world's population in 1950 (56%) and 2000 (55%); just over 40% of it was from China, whose percentages decreased from 26% to 24%, respectively. There was also a drop of 2% in the USA, but with a relatively smaller base, 16% less. Its percentages were double that of Japan, the least populous, 5% and 4%. This total 5% decrease more than offset the rise of 4% in India, from 15% to 19%. The forecast for 2050 shows that India will edge out China, 21% versus 19%. Compared to 2000, the USA is expected to have no change, 8%, whereas Japan will continue the drop of 1%.

Would you mind posting a sample essay, please? Thank you so much.