Imprisonment rates across five different nations from 1930 to 1980

The bar chart illustrates the number of prisoners in five countries—Great Britain, Australia, New Zealand, the United States, and Canada—between 1930 and 1980.

Overall, the United States experienced the most significant fluctuations in imprisonment figures, while Great Britain showed a consistent upward trend throughout the period. By the end of the period, the United States recorded the highest number of prisoners, whereas Australia saw the lowest.

In 1930, Canada had the highest imprisonment rate at 120, followed by the United States and New Zealand at 100 each. Great Britain started with the lowest figure of 30. By 1950, the figures for most countries had declined or remained relatively stable, with the United States at 105 and Canada at 115. Conversely, Great Britain’s figures began a steady climb, rising from 30 in 1940 to 50 by 1960.

By 1980, the United States reached a peak of 135, having recovered from a dip to 85 in 1970. Great Britain continued its upward trajectory, reaching 85. Meanwhile, Australia’s figures fluctuated, dropping to 50 by 1980, while New Zealand’s figures rose to 87. Canada’s imprisonment numbers remained relatively high, finishing at 90 in 1980 after a low of 85 in 1970.