Describing Line Graphs (1)
Look at the following simple line graph:
It shows the population of Denmark from 1996 to 2007. You can see that in 1996 the population was 5.25 million and that by the year 2007 it had grown to 5.45 million.
When you write about a line chart it is important to look first at the Chart Title. This tells you what information the graph displays and you can use this information in your description.
Then look at the X and Y axes. The titles of these axes sometimes give you information you can use in your description. It is important also to look at the UNITS. On the Yaxis in this graph the units are millions. The population of Denmark in 1996 was not 5.25, but 5.25 million people.
Line graphs describe change. When describing these graphs you must answer the question, "What changed?". In this case we can see that the population of Denmark increased from 1996 to 2007.
We can also ask the question, "How did the population change?". Because the line is fairly smooth, we can say that the population increased steadily.
Lastly, we can ask the question, "How much?". In this case, "How big was the change in population?" The population in 1996 was 5.25 million and in 2007 it was 2.45 million. So there was an increase of 0.2 million or 200,000 people.
To write a short description of this graph ask yourself (and answer!) the following questions:
 What exactly does the graph show? (Use the chart title to help you answer this question)
 What are the axes and what are the units?
 What changed?
 How much did it change?
Answering these questions will help you to write a short description of this simple graph.
Here is an example:
This graph shows population change in Denmark from 1996 to 2007. Denmark's population grew steadily from 5.25 million in 1996 to 5.45 million in 2007, an increase of 200,000 people.
Vocabulary
Other words you can use instead of increased or grew are rose and went up.
Adverbs you can use with these words are:
How? 
How much? 

increased 
dramatically, significantly, considerably, rapidly, substantially, steadily, sharply, markedly, greatly, slightly, exponentially, proportionally, strongly  by X% (by X per cent), by X (units), from X to Y, tenfold, fourfold ... 
grew 
rapidly, steadily, slowly, gradually, dramatically, substantially, enormously, quickly  by X% (by X per cent), by X (units), from X to Y 
rose 
sharply, slowly, steadily, slightly, rapidly, quickly, dramatically, significantly, substantially, gently, fractionally, considerably, gradually  by X% (by X per cent), by X (units), from X to Y 
went up 
The above adverbs are not usually used with "went up".  by X% (by X per cent), by X (units), from X to Y 
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