Hi mediahelp!
I think there has been a great decrease in the broadcasting of TV dramas. Because people aren't as interested in them anymore.
Back in the day the whole family would sit around the TV on a Sunday night and watch dramas together. But nowadays each person in the hosuehold probably has a TV and they all want to watch different programmes such as reality TV or soaps. We also now have the interent and computer games that people want to use instead of watching dramas on TV. Reality TV is taking over the television industry, as audiences want to watch programmes on real people. TV dramas are often only aimed at particular audiences, not many of them appeal to teenagers or children.
Hope that helps a bit!