 Chart positions listed here are provided by the Oricon Weekly Singles and Albums Charts, started in 1968 and 1970, respectively.The Japanese albums chart had been separated into LPs (started in 1970), cassette tapes (introduced in 1974), and compact discs (launched in 1985) charts until they were unified in January 1987.For the albums released before 1987, the position on the LP chart are prioritized in principle, except for the materials not issued on vinyl.