By December 31, 2000, there will be at least 10,000 persons in cryonic suspension. A person who has been revived, but was in suspension for at least one year, counts as suspended. Except for revivals and attempted revivals, a person removed from suspension does not count. Whether a person is suspended or held by a recognized cryonics organization is immaterial. Suspension includes any method of pausing or slowing metabolism by at least 90%, including freezing, chemical fixation, suspended animation, high pressure, cooling, relativistic time dilation, or any combination. As of October 1994, about 55 persons are known to be frozen, some as heads.