Pad number of records with 0 when there are none

Hi, I am creating a line graph that counts # of errors weekly.  When no errors exist for a week, it does not plot that week and plot the next available week.  But I need it to plot a zero for the week no errors exist.  For example below, see the orange line.  There was 1 error in week of Mar 8th, no errors in March 15 and 2 errors in Mar 22.  I need it to plot 0 for March 15.

How do I do this?