From U.S. gov't. web site: "U.S. adult population grows by about 2 million / yr. which means 1.3 million jobs/year need to be created." I suppose their claim about jobs needed takes into account retirees and disabled adults, etc...I hope this helps answer your original question.
Later in same report, "In 2011 & 2012 we've averaged 155k jobs / month - nearly half of what is required to keep up with population growth in a healthy economy."
"5.4 million people on benefits, 2.1 million of which are on extended Fed. Emergency Aid."
"In the past 2 years we've been averaging 360k-390k new unemployment apps./week..."
By my math that means 375k x 4.3 wks. in a month = 1.613 million applications/month.
"Since the end of the recession in mid '09, the work force has declined by 8 million."