Demographers studying the current population of a particular country produce the age-structure diagram shown in the figure below: Population pyramid for a country. The pyramids base shows that approximately 4 million males and 4 million females in the country are 0 to 5 years old. The next two levels of the pyramid are narrower; then the pyramid becomes wide again, representing approximately 4.2 million males and 4.2 million females between 15 to 20 years old. The pyramid reaches its widest point at the next level, which represents the men and women between 20 to 25 years old; it then becomes increasingly narrow before becoming wide again at the level that represents the men and women between 45 to 50 years old. The pyramid then becomes increasingly narrow; the levels for men become narrower than the levels for women.

Which of the following conclusions is not supported by this diagram?

The birth rate has increased during the past 10 years.
Approximately the same number of boys as girls were born in the past 20 years.
The country has experienced two population "booms" approximately 25 years apart.
There are nearly twice as many 70 to 74-year-old men than women in the same group.