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]
(..) Yeah, I work better at night. And these soil samples just arrived from the Bindura plateau. Ah, Zimbabwe. Their crops have been overrun by disease for decades. Well... ...your work will put an end to that. - That's the hope. - That's the reality. Are you from the foundation? They (..)1998 TvShow: Charmed Title: The Truth Is Out There... and It Hurts Season: 1 Episode 8