Re: Lies, damned lies, and statistics that don't lie.
While you can block ping and there could be good reasons to do so. Typically on BGP4 routers belonging to Internet providers. Mostly it is the last thing you want do. You want ping, traceroute and DNS working just to be sure your public facing services are up. Theregister.co.uk is pingable. But most addresses are not servers. They are ISP home routers with NAT.
How do you expect your ISP to provide support if you block ping?
So if 70% of addresses are not pingable, it is fair to guess 69% are not directly routable and could be reallocated.