The CHART Procedure

Results

Missing values are not considered as valid levels for the chart variable when you use the MISSING option.
Missing values for a GROUP= or SUBGROUP= variable are treated as valid levels.
PROC CHART ignores missing values for the FREQ= option and the SUMVAR= option.
If the value of the FREQ= variable is missing, zero, or negative, the observation is excluded from the calculation of the chart statistic.
If the value of the SUMVAR= variable is missing, the observation is excluded from the calculation of the chart statistic.