DATA work.essence ;
	SET sashelp.citimon 
            (WHERE = (date BETWEEN "01jan1980"d AND "31dec1981"d)) ;
	IF MONTH(date) IN (7,8) THEN eegp = . ;
	LABEL eegp = "Prix de l'essence" ;
RUN ;
SYMBOL1 I = JOIN C = GREEN L = 3 ;
SYMBOL2 I = JOIN C = BLUE W = 2 ;
PROC GPLOT DATA = work.essence ;
	PLOT eegp * date ;
	PLOT2 eegp * date / SKIPMISS ;
RUN ; QUIT ;