Every four years, this number is cut in half.
It's not accurate. The halving occurs every 210,000 blocks which takes roughly 4 years.New bitcoins are issued by the Bitcoin network every 10 minutes.
This is wrong too. New bitcoins are generated in every block mined. It's estimated that a new block is mined every 10 minutes on average. A new block may be mined in a few seconds. It's also possible that it takes an hour.