Maths : Data Interpretation

Q 5 / 46

Consider the following data:

Year Birth rate Death rate
1911–1921 48.1 35.5
1921–1931 46.4 36.3
1931–1941 45.2 31.2
1941–1951 39.9 27.4
1951–1961 41.7 22.8
1961–1971 41.1 18.9
1971–1981 37.1 14.8

For which period was the natural growth rate maximum?