About $1 billion was spent on the project in the past decade.

For the past 3 decades we seem to have been trying to do both.

Indeed, another problem is the changes in the students over the past three decades.

Over the past six decades, few changes have been made to the building.

The political, social, economic and religious world had changed over the past decades.

Over the past two decades, Americans and their jobs have changed a great deal.

What had his life been like for the past decade?

What had the man been doing for the past two decades?

Only three states have done so in the past decade.

The world had become a less certain place over the past decades.