No significant changes are expected in the shipping market in the next few years from the gradual withdrawal of single-hull tankers and the enforcement of new regulations limiting the shipping of some heavy forms of oil, according to industry analysts. However, certain unsolved issues might affect procedures, such as the definition of the authority to enforce regulations, as the tanker withdrawal agreement has not been signed by all countries. This means some tankers might be able to evade the regulations agreed for some time. Sources inside Intertanko, the International Association of Independent Tanker Owners, suggest that a large number of single-hull tankers have already been withdrawn as shipowners have long begun preparations for adjusting to the new requirements for double-hull vessels. Independent shipowners and their managing companies intend to upgrade their fleets to improve their position in global competition, as well as to be fully harmonized with the regulations for naval environment protection and cargo and crew safety. For 2005, 169 ships are reportedly planned for scrapping, with a total capacity of 6.9 million dwt, out of which 142 tankers belong to the under-60,000 dwt category. This means, the same sources report, that only 27 ships remain of the Panamax, Aframax, Suezmax or larger type, a number which could be considered negligible in terms of the overall world fleet. According to Intertanko data, at the end of 2004 some 67 percent of the global tanker fleet were double-hulled; by the end of this year this is expected to rise to 71 percent.