Because GFIs were not mandatory on all outlets back then and what exists is automatically grandfathered in when the rules change. Maybe in your meter box there are actually GFIs on all circuits, they just never put the grounded sockets in.
Look for green marked groups or groups with test buttons. Those are the ones that are the most safe to use.
But do check behind your sockets, there is a chance you may have the ground wires already pulled in and they just saved on the sockets.
I have the opposite problem here: I have all of my outlets on GFIs and there are ground wires everywhere. But the system is sensitive enough that I can't use my 10KA spotwelder because the phase lag is such that the system thinks there is a leak when there really isn't.
Look for green marked groups or groups with test buttons. Those are the ones that are the most safe to use.
But do check behind your sockets, there is a chance you may have the ground wires already pulled in and they just saved on the sockets.
I have the opposite problem here: I have all of my outlets on GFIs and there are ground wires everywhere. But the system is sensitive enough that I can't use my 10KA spotwelder because the phase lag is such that the system thinks there is a leak when there really isn't.