Graph and Chart: The expenditure and consumption on fast foods

The Chart below shows the amount of money per week spent on fast fods in Britain. The graph shows the trends in consumption of fast foods.
Write a report for a university lecturer describing the information shown below.
The graph illustrates the consumption trends in three different kinds of fast food, fish and chips, hamburgers, and pizza. From the graph, in 1970, the amount of fish and chips consumption was the highest, approximately 300 grammes, while the amount of hamburgers consumption and pizza consumption each was below 100 grammes. Nevertheless, from 1997-1990, the trend in consumption of fish and chips obviously decreased, it reduced to about 230 grammes in 1990, while those of hamburgers and pizza significantly rose to over 500 grammes and over 200 grammes respectively in 1990.
Moreover, the chart also shows weekly expenditure on these fast foods in Britain. Three separated groups, high income, average income, and low income, were depicted in the chart. Evidently, the expenditure on hamburgers and pizza directly relate to the income. People consume these two types of fast food more when they have more money, especially on hamburgers which the expenditure increases from 14 pence, in low income group, to 40 pence person per week, in high income group. However, the chart shows that the amount of money spent on fish and chips does not relate to the income level.

TOEFL listening lectures: To which entertainment does the lecturer not relate Greek drama?

@Omo37 : this is just my personal suggestion. I think you should discuss the charts in the same order they are shown in the exam. I’m not saying your method is bad but this is safer from my viewpoint.
You can write this for the second paragraph:
“The chart shows the expenditure based on different income groups.”
and then for the last paragraph, you can write:
"The trends in consumption of fast foods are reflected in the second graph. "

You can take a look at: