According to Bureau of Labor Statistics figures released on Friday, last year saw the second-smallest number of major strikes in recorded history: seven. This is close to the record low set in 2009, five — in the depths of the Great Recession, when the unemployment rate was approaching 10 percent. Last year’s average unemployment rate was less than half that, 4.3 percent.

Here’s the grim history of the decline of labor’s most powerful weapon in two graphs: