I guess the only minute difference would be how we use them. The concept of Decade: From the perspective of calendar units, "decade" is a calendar unit in ten years, the same is lustrum (5 years), century (100 years), millennium (1000 years). First of all, the last few decades and the past few decades are the same, so the question becomes the difference between in and over in the past period of time. Both can be translated as in/within the past few decades, using in to mean in.
Honolulu Hawaii Obituaries Hawaii Newspaper Obituaries Hawaii
In the/this decade = in these 10 years this implies you're talking about the current decade. In a decade = in 10 years time this has no specific date. I mean we can say two decades or three decades to.
