Answer:
The birth rates have been declined.
Explanation:
According to the statistics of the cabinet office, government of Japan, the birth rates have been declined from 4.32(at 1947～1949) to 1.26(minimum rate, at 2005).
In my opinion, the main reasons are as follows:
(1) After the economic ressesion, more and more young people have to work as non-regular workers. The situation leads to the poverty, and non-regular workers cannot afford to get married.
(2) In Japan, raising and educating children is extremely expensive, compared to many western countries.
Therefore, more women have taken up a career in society and it led to the low birth rates.