LOS ANGELES - British singer Adele’s multi-platinum selling album “21” scored its 16th week at No. 1 on the Billboard 200 album chart on Wednesday, entering an elite list of only five albums to cross that mark in the past 20 years. “21,” which has been selling more than 100,000 copies each week for 33 weeks, joined the ranks of the soundtrack to the 1997 box-office phenomenon “Titanic,” Whitney Houston’s soundtrack to 1992 film, “The Bodyguard,” country crooner Garth Brooks’ “Ropin’ The Wind” and Billy Ray Cyrus’ “Some Gave All,” also in 1992, all of which crossed 16 weeks at No. 1.