How many labor strikes are there per year?

19 major strikes in the US in 2012

Not too many people know the fact that in 2012, in the US there were 19 major strikes and lockouts.  More than 148 000 workers were in strike.  Moreover, the strikes lasted at least one shift.  Keep in mind that in 2011 there were also 19 major work strikes.  More than 113000 persons were in strike in 2011.  It is extremely interesting to mention the fact that over 40 percent of major work stoppages beginning in 2012 occurred in November and December.