data sasuser.smoking;
INPUT Year Rate;
Since_74 = Year - 1974;
LINES;
1974 52
1975 47
1976  .
1977 45
1978 47
1979 44
1980 41
1981 45
1982 42
1983 41
1984 39
1985 39
;
Run;

PROC REG DATA=SASUSER.smoking;
 model Rate = Year ;
RUN;


PROC REG DATA=SASUSER.smoking;
 model Rate = Since_74 ;
RUN;