The 'decade' of the 1920s runs from January 1, 1920 to December 31, 1929.
There have been a lot of changes during/in/over the past two 'decades'.
a 'decade' of drought [=a drought that lasted 10 years]
(..) I'm asking why you did it. Look, the arrival of strong artificial intelligence has been inevitable for decades. The variable was "when," not "if." So I don't see Ava as a decision, just an evolution. (..)2014 Ex Machina