There was a period in the 1960s, 1970s and early 1980s when Nikon’s sales were relatively low, and primarily to professionals and high-end enthusiasts. Then, there was a film boom, driven by the development of lower-cost point-and shoot film cameras. This started about 1985, peaked about 1995, and was gone by about 2001. It wasn’t a high peak- more rounded off looking.
Then, starting in the very late 90s, digital cameras came onto the scene, and there was a HUGE boom- when the digital era got going and film/digital overlapped, their sales were still almost as large as they’d been in 1995 when film cameras were at their peak.
From there, it went crazy, and both digital p&s and DSLR sales climbed rapidly until about 2013, when smartphones stole their thunder, and their sales declined almost as fast, leaving Nikon with sales numbers for their high-end DSLRs and mirrorless cameras that were oddly similar to the ones prior to the film boom in 1985.
