create cursor mycursor (year i,saled i, growth I)

...
SELECT MyCursor 
GO TOP    && Important
m.lnOldYear = Saled
SCAN
    REPLACE growth WITH ((Saled- m.lnOldYear)/m.lnOldYear * 100)
    m.lnOldYear = Saled
ENDSCAN
BROWSE NORMAL

Two comments;

1) the SELECT myCursor is not necessary above as the CREATE CURSOR will do that in the current work area
2) The GO TOP is not only not Important, it is not needed at all as SCAN always starts at top unless you use the WHILE or REST clauses