The Cold War was a period of great unrest at home and abroad, as fears and concerns of potential nuclear war between the United States and the Soviet Union dominated world news. The United States and Great Britain allied themselves in opposition to Soviet nuclear proliferation, while Gorbachev struggled at home with a failing economy and was unable to continue the pace of the current arms race. The Cold War was in the forefront of world news for much of the 1980s and was a defining theme of the Reagan presidency.
Below is a Ngram comparing mentions between Cold War leaders Ronald Reagan, Margaret Thatcher, and Mikhail Gorbachev. As the race to the end of the Cold War escalated in the 1980s, all three leaders mentions spike in an upward trend. The peak for all three leaders came in 1988. U.S. President Reagan was mentioned at a substantially higher rate than Soviet President Gorbachev and British Prime Minister Margaret Thatcher.
I did not experience any difficulty with producing a chart with the Ngram viewer. It was very easy, once I picked my time period and what I wanted to compare, to produce a the Ngram line graph. You can scroll over any part of the lines to see the progression of the number of hits tabulated for each leader.
Below is a bar chart from the Proceedings of the Old Bailey from 1776-1876. The chart quantifies how many men aged 15-30 received the death penalty for murdering women of any age. As you can see, 1860 saw the greatest number of men who were executed for the murder of women.
The Old Bailey chart makes deciphering the data a little more difficult, as it does not provide x and y axis data. One must refer to the key below the chart to understand what the bar graph is demonstrating.
In summary, there are a variety of options available for graphing and charting data, and one must explore all options to determine which service will produce the most efficient way to display data and convey the intended message effectively.