11% decline in out of pocket drug spending in the US, led by declining generic prices
Generics are 80-90% of prescriptions. From 2008 to 2016 a basket of generics declined in price by 62% (http://lab.express-scripts.com/~/media/PDFs/Drug%20Trend%20Report/ExpressScripts_DrugTrendReport_Highlights.ashx). BLS survey claims out of pocket spending on drugs decreased 11% from 2013 to 2018.
Of course, for out-of-pocket comparisons we should care about cost to insurance companies and if consumption increased or decreased as well.