I have not gotten a call from them since I go the put on the national DNC list.
Before that I used to get calls a couple of times day from these people. Worst part is, you say hello and get this loud Cruise Ship Horn in your ear before the automated message comes on.
All zeros usually means caller is using skype out or some other voip service and are probably phone solicitors. Some companies think they can get around DNCL this way but if you report them they will be subject to some pretty large fines.