Simplify the following text for a Grade 8 native English-speaking person.
Original: The policy was introduced in 1978 and initially applied to first-born children in the year of 1979 . It was created by the Chinese government to alleviate social , economic , and environmental problems in China , and authorities claim that the policy has prevented between 250 and 300 million births from its implementation until 2000 , and 400 million births from 1979 to 2010 .
Simplified: Since 1979 , the policy has prevented 250 million births from occurring .