SELECT DISTINCT l.name,  CAST( l.einwohner AS integer) AS Land_Einw,  CAST( SUM(lt.einwohner) AS integer) AS LT_Einw ,
                CAST( (SUM(lt.einwohner) / l.einwohner) AS decimal(20,2)) AS VERHAELTNIS_LT_zu_LAND
FROM   land l, landesteil lt
WHERE  l.l_id = lt.l_id
    
GROUP BY l.name, l.einwohner
HAVING  ((SUM(lt.einwohner) / l.einwohner) > 1.1)
   OR   ((SUM(lt.einwohner) / l.einwohner) < 0.9);