According to a recent study, in 2012:

• The total cost of medicines declined by 3.5% on a real per capita basis, to $325.8 billion
• Lower-cost generics accounted for 84% of all prescriptions
• The average pharmacy benefit co-pay declined by $2 to $121
• Patients filled 72% of all retail prescriptions with a co-pay of $10 or less

Source: "IMS Health Study Points to a Declining Cost Curve for U.S. Medicines in 2012," IMS Institute for Healthcare Informatics Press Release, May 9 2013, http://www.imshealth.com/portal/site/ims/menuitem.d248e29c86589c9c30e81c033208c22a/vgnextoid=8659cf4add48e310VgnVCM10000076192ca2RCRD&vgnextchannel=437879d7f269e210VgnVCM10000071812ca2RCRD&vgnextfmt=default