Need to get distribution curve to work when count is 0

I am trying to create a distribution curve for performance ratings. It looks good when there is a count >0 for each rating but when there is a 0 count for Unsatisfactory, I drops it from the distribution. It is needed so the skew can be visualized. Here is what it looks like:

And here is the SQL:
SET VARIABLE PREFERRED_CURRENCY='User Preferred Currency 1';SELECT s_0, s_1, s_2 FROM (
SELECT UNSUPPRESSED
0 s_0,
CASE WHEN "Workforce Performance - Performance Rating Real Time"."- Rating Level"."Numeric Rating" =0 THEN '0' WHEN "Workforce Performance - Performance Rating Real Time"."- Rating Level"."Numeric Rating" =1 THEN '1 Unsatisfactory' WHEN "Workforce Performance - Performance Rating Real Time"."- Rating Level"."Numeric Rating" =2 THEN '2 Improvement Needed' WHEN "Workforce Performance - Performance Rating Real Time"."- Rating Level"."Numeric Rating" =3 THEN '3 Achieves' WHEN "Workforce Performance - Performance Rating Real Time"."- Rating Level"."Numeric Rating" =4 THEN '4 Exceeds' WHEN "Workforce Performance - Performance Rating Real Time"."- Rating Level"."Numeric Rating" =5 THEN '5 Exemplary'