The highest-selling albums and EPs in the United States are ranked in the "Billboard" 200, which is published by "Billboard" magazine.
 The data are compiled by Nielsen Soundscan based on each album's weekly physical and digital sales, as well as on-demand streaming and digital sales of its individual tracks.
 In 2015, a total of 39 albums claimed the top position of the chart.
 One of which, American singer Taylor Swift's "1989" started its peak issue dated November 15, 2014.
<ref name="1/3/15"> </ref> "1989" was the longest-running number-one album of the year, staying atop the chart for six weeks and was the best selling album of 2015 before Adele's "25", which managed to surpass the album's sales but after the year-end cut-off.
 Canadian hip hop soul artist Drake's fourth commercial release, "If You're Reading This It's Too Late", became the third best-selling overall album and top-selling digital album with 535,000 digital units sold, 495,000 of which consisted of traditional whole album sales.
"City on Our Knees" is a song by Christian artist TobyMac from his album, "Tonight" (2010).
 It was released as a radio single in August 2009 and reached No. 1 on "Billboard"' s Hot Christian Songs chart in October 2009.
 It also reached No. 8 on Billboard's Heatseekers Songs.
 The song was nominated for a Grammy Award as the Best Gospel Song.
 The song also charted at No. 11 on the Bubbling Under Hot 100 Singles chart.
 The song sold over 17,000 digital units in its first week.
 As of February 20, 2010, the song has sold over 225,000 copies, making it the fastest charting and selling track of tobyMac's career.
 It won a Dove Award for Pop/Contemporary Song of the year.
"Cold" (originally "Theraflu" and then "Way Too Cold") is a song by American hip hop recording artist Kanye West, released as the second single from the album "Cruel Summer" (2012).
 The song, which features DJ Khaled, was made available for purchase on the iTunes Store on April 17, 2012.
 Songwriting is credited to West, Chauncey Hollis, James Todd Smith and Marlon Williams, while production was handled by Hit-Boy.
 Lyrically, the song features West boasting about his personal issues and touching on subjects such as his relationship with Kim Kardashian, his breakup with Amber Rose, and his feelings on Wiz Khalifa and Kris Humphries.
 The song received positive reviews from music critics, who praised West's lyrical performance and the boldness of his subject matter.
 The song contains an interpolation of "Lookin' at Me" (1997) as performed by Mase and Puff Daddy, and a sample of "Illegal Search" (1990) also performed by LL Cool J.
"Run This Town" is a song by American rapper Jay-Z.
 The song also features Kanye West and Rihanna.
 It was written by the performing trio, with assistance from Ernest Wilson and Jeff Bhasker.
 Production of the track was made by West and Wilson (also known as "No I.D.").
 "Run This Town" was released as the second single from Jay-Z's eleventh studio album "The Blueprint 3", and is used as the theme song of "Battlefield 4".
"Niggas in Paris" (edited for radio as "In Paris" or simply "Paris"; censored on the album as "Ni**as in Paris") is a song by American rappers Kanye West and Jay-Z from their collaboration album "Watch the Throne" (2011).
 The song heavily samples "Dirty South Bangaz" by Big Fish Audio and also contains samples from "Baptizing Scene" by Reverend W.A. Donaldson, "Victory" by Puff Daddy featuring The Notorious B.I.G. and Busta Rhymes and also samples dialogue from DreamWorks Pictures' 2007 film "Blades of Glory".
 On the week of the album's release the song debuted at number 75 on the US "Billboard" Hot 100 eventually peaking at number 5.
 As of May 2017, it has sold 5 million digital units in the United States.
 The single won Best Rap Performance and Best Rap Song at the 55th Annual Grammy Awards.
Chauncey Hollis, Jr. (born May 21, 1987), better known by his stage name Hit-Boy, is an American record producer, rapper, singer and songwriter from Fontana, California.
 In May 2011, Hollis had signed a deal with Kanye West's GOOD Music production wing, known as Very G.O.O.D. Beats and left the label after his contract expired in June 2013.
 In December 2012, it was revealed he had signed a recording contract with Interscope Records, and subsequently founded his own record label imprint, Hits Since '87.
 He is perhaps best known for his production catalog, which includes "Niggas in Paris" by Jay-Z and Kanye West, "Drop the World" by Lil Wayne and Eminem, and the GOOD Music single "Clique", all of which have been certified platinum or higher by the Recording Industry Association of America (RIAA).
"Can't Tell Me Nothing" is a song by American hip-hop recording artist Kanye West.
 It was released on May 15, 2007 as the lead single of his third studio album, "Graduation".
 The song was produced by Kanye West and Atlanta record producer DJ Toomp.
 It received acclaim from music critics and was listed amongst the best tracks of the year by several publications.
 "Can't Tell Me Nothing" was nominated for Best Rap Song at the 50th Grammy Awards, but lost to another one of West's songs, "Good Life".
 Since its release, West has continually reiterated that it is his favorite song he's done.
 In 2012 Complex named it their song of the decade.
"Swagga Like Us" is a song by American hip hop recording artists Jay-Z, T.I., Kanye West, and Lil Wayne.
 It was released on September 6, 2008 in the United States as the fifth single from T.I.'s album "Paper Trail", and was also slated for inclusion on Jay-Z's eleventh album "The Blueprint 3" (2009), although it ultimately did not make the final track listing.
 The song was produced by West and is constructed primarily around a vocal sample of "Paper Planes" by British musician M.I.A.
The Watch The Throne Tour was a co-headlining concert tour by American rappers Jay-Z and Kanye West that began on October 28, 2011 in Atlanta and continued until June 22, 2012 with its final show scheduled in Birmingham.
 Originally scheduled for 23 performances, the tour was expanded to 34 performances in North America due to heavy demand for tickets; 29 shows were confirmed in the United States with 5 shows in Canada.
 Following massive success in the United States and Canada, Jay-Z & Kanye West announced the European leg of the tour on February 21, 2012 which featured 23 performances, bringing the number of shows to 57 at the time.
The Meadows Music & Arts Festival is an annual music festival held at Citi Field in Queens, New York City.
 The festival was produced by Founders Entertainment, which also produces the Governors Ball Music Festival.
 The inaugural year of the festival, which was held on October 1–2, 2016, was headlined by several artists, including: Kanye West, J.Cole, Kygo, and Chance the Rapper.
 The festival boasted 42 artists and four stages: Linden Blvd., Queens Blvd., Shea, and The Meadows.
 The festival was inspired by the cancellation of Kanye West's set during the Sunday of the 2016 Governors Ball Music Festival due to heavy rains.
 In was announced on March 20, 2017 that the festival will return September 15–17, 2017.
 On May 8, 2017, the official lineup was announced, featuring headliners Jay-Z, Red Hot Chili Peppers, and Gorillaz.

Question: As of May 2017, how many digital units in the United States has the Jay-Z and Kanye West song that Chauncey Hollis, Jr is best known for sold?
Answer: 5 million