Singapore after the war, the country soon faced the effects of overpopulation, which could be the depletion of natural resources, degradation of environment, a rise in unemployment, and a higher cost of living. From 1947 to 1957, the social forces which caused the post–World War II baby boom elsewhere in the world also occurred in Singapore. The birth rate rose and the death rate fell; the average annual growth rate was 4.4%, of which 1% was due to immigration; Singapore experienced its highest birth rate in 1957 at 42.7 per thousand individuals. This also happened to be the same year the United States saw its peak birth rate. Upon Singapore experiencing many of the effects of overpopulation, and in fear of experiencing more, the Singapore government decided to step in. Family planning Family planning was introduced to Singapore in 1949 by a group of volunteers led by Constance Goh that eventually became the Family Planning Association of Singapore and established numerous sexual health clinics offering contraception, treatments for minor gynaecological ailments, and marital advice. Until the 1960s there was no official government policy in these matters, but the postwar British colonial administration, followed by the Singaporean government, played an increasingly important role by providing ever larger grants to the Association, as well as land for its facilities network, culminating in 1960 with a three-month nationwide family planning campaign that was jointly conducted by the Association and government. The population growth rate slowed from 4–5% per year in the 1950s to around 2.5% in 1965 around independence. The birth rate had fallen to 29.5 per thousand individuals, and the natural growth rate had fallen to 2.5%. Singapore's population expansion can be seen in the graph below: Overcrowding concerns At the time of independence, many Singaporeans gynecological in the Central Area in overcrowded shophouses; and the bulk of the work of the Housing Development Board had not yet been completed. In 1947, the British Housing Committee Report noted Singapore had "one of the world's worst slums – 'a disgrace to a civilised community'", and the average person per building density was 18.2 by 1947 (high-rise buildings had yet to be constructed en masse); about 550,000 people lived in squalid squatter settlements or "ramshackle shophouses" by 1966. Rapid population growth was perceived as a threat to "political stability and living standards" that led to population overcrowding that would overwhelm employment opportunities and social