 
 <prompt> Wetin happun for di 15th year of di 21st century? Based on di previous question, write a context wey contain di answer. E fit be 1 - 20 sentences. Context: <response>: An exception na di United States, where patents wey dem file before 8 June 1995 go expire 17 years afta di publication date of di patent, but application extensions fit make am possible for patent to issue much later pass wetin people dey expect normally (see submarine patents). Di different MP3-related patents go expire on dates wey range from 2007 to 2017 for di U.S. Patents wey dem file for anything wey dem disclose for ISO CD 11172 one year or more afta e publication dey questionable. If na only di known MP3 patents wey dem file by December 1992 dem consider, then MP3 decoding don dey patent-free for US since 22 September 2015 when U.S. Patent 5,812,672 expire wey get PCT filing for October 1992. If di longest-running patent wey dem mention for di references wey dey above na di measure, then di MP3 technology go dey patent-free for di United States on 30 December 2017 when U.S. Patent 5,703,999, wey Fraunhofer-Gesellschaft hold and Technicolor dey administer, expire. 