St. Paul (KMKO)-The jobless rate for greater Mankato is at its lowest point in three and a half years.  Unemployment figures released yesterday by the Minnesota Department of Employment and Economic Security shows the April jobless rate for greater Mankato was 4.2%.  The last time it was lower was in October 2008, with a rate of four percent.  Last month's jobless rate was down from 5.1% in March.  The rate a year ago was also 5.1%.