<prompt> unaweza kugeuza matini haya ya swahilikwa kiingereza?chelsea, kwa mara ya kwanza ilipata mafanikio makubwa mwaka 1955, ambapo walipata ubingwa wa ligi, na walishinda mataji kadhaa katika miaka ya 1960, 1970, 1990 na 2000.  <response>: the club had its first major success in 1955, when they won the league championship, and won several cup competitions during the 1960s, 1970s, 1990s and 2000s. 