title 'Senic example #1'.
data list file='senic.dat' free
         / id stay age infrisk culratio xratio nbeds medschl
           region census nurses service.
missing values  stay,age culratio,xratio (9999) infrisk(999)
                nbeds to census, service (9) nurses (0,.999).
frequencies variables=all.
descriptives variables=all.