For patient born between Year 1930 to 1940, how many percent of them were inpatient?
patient born between Year 1930 to 1940 refers to year(Birthday) BETWEEN '1930-01-01' AND '1940-12-31'; inpatient refers to Admission = '+'
SELECT CAST(SUM(CASE WHEN Admission = '+' THEN 1 ELSE 0 END) AS REAL) * 100 / COUNT(*) FROM Patient WHERE STRFTIME('%Y', Birthday) BETWEEN '1930' AND '1940'