The earliest census taken in Taiwan recorded the population at 3.12 million in 1905. After 40 years, the figure nearly doubled to 6.02 million. In 1964, the government began encouraging family planning, easing the pressure on population growth. The natural population growth rate fell from 3.158 percent in 1961 to 0.68 percent in 1998. Although the figure rose to 0.81 percent in 2000, it declined to 0.59 percent in 2001 due to a decrease in the birth rate, which dropped from 1.38 percent to 1.17 percent during the same time period. Meanwhile, the death rate rose slightly from 0.568 percent in 2000 to 0.571 percent in 2001.

Clearly, Taiwan's population structure has undergone great changes over the last few decades. As those born during the baby boom have grown up, the economically productive 15-64 age group increased to 70.38 percent of the total population in 2001. Meanwhile, the proportion of dependents dropped from 64 percent in 1975 to 42 percent in 2001. Longer education, delayed marriages, and comparatively fewer potential mothers between the ages of 20 and 34 have reduced the birth rate. Since 1984, the population replacement rate has remained below 1 percent, dropping to 0.7 percent in 2001.