how frequent do they publish?
Weekly.
Billboard 200
The Billboard" 200 is a record chart ranking the 200 most popular music albums and EPs in the United States. It is published weekly by "Billboard" magazine. 
who is elvis presley? He was an American singer, musician and actor. which was his debut album? Elvis Presley. what are some of his achievements? Best-selling solo artist and the most albums charting in the "Billboard" 200. who publishes this record chart ranking? Billboard magazine.
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Billboard 200 [SEP] Introduction
The Billboard" 200 is a record chart ranking the 200 most popular music albums and EPs in the United States. It is published weekly by "Billboard" magazine. It is frequently used to convey the popularity of an artist or groups of artists. Often, a recording act will be remembered by its "number ones", those of their albums that outperformed all others during at least one week. The chart grew from a weekly top 10 list in 1956 to become a top 200 in May 1967, and acquired its present title in March 1992. Its previous names include the Billboard" Top LPs (1961–72), Billboard" Top LPs & Tape (1972–84), Billboard" Top 200 Albums (1984–85) and "Billboard" Top Pop Albums.