When, Why glass milk bottles were replaced with plastic bags ?

Once milk, yogurt, fermented baked milk, cream sold in glass bottles .For milk were liter and half liter .Then they were replaced by " pyramid " of a special board, comfortable in application, were not dropped, then it was the turn of plastic bags .When they get there, and why?

How many in Russia in 2015 rose dairy products ?

How many in Russia in 2015 rose dairy products ?