ARS Technica predicts the supply of IPv4 addresses will dry up within just a couple of years. As we enter the new year only 722 million of the 3.7 billion usable IPv4 addresses are left, compared to close to 2.1 billion addresses that were still available ten years ago.
1,370 million IPv4 addresses were used up this past decade. We have 722 million left, so the bottom of the pool is in sight.
There are 3,706,650,624 usable IPv4 addresses. On January 1, 2000, approximately 1,615 million (44 percent) were in use and 2,092 million were still available. Today, ten years later, 2,985 million addresses (81 percent) are in use, and 722 million are still free. In that time, the number of addresses used per year increased from 79 million in 2000 to 203 million in 2009. So it's a near certainty that before Barack Obama vacates the White House, we'll be out of IPv4 address. (Even if he doesn't get re-elected.)