Several people have mentioned gaming, but it's more than just an outlet.
People spend a lot more time indoors due to video games and the internet. Fewer interactions mean less random third party crime. Also, credit cards credit / debit cards reduced the amount of cash people walk around with at the same time stuff became less valuable. So there is just less money to be made robbing people / houses.
People spend a lot more time indoors due to video games and the internet. Fewer interactions mean less random third party crime. Also, credit cards credit / debit cards reduced the amount of cash people walk around with at the same time stuff became less valuable. So there is just less money to be made robbing people / houses.