It appears that you are talking about the popularity of LPs, or vinyl records, in the music industry. In 1973, LPs were the most popular format for listening to music, with over 80 million units sold. However, over the next 15 years, their popularity began to decline, and by 1988, sales had fallen to around 40 million units. By 1997, sales of LPs had reached their lowest point and were no longer being produced.

The decline in LP sales can likely be attributed to a number of factors, including the increasing popularity of other music formats such as CDs and MP3s, as well as the convenience and portability of digital music. Additionally, the cost and difficulty of producing and distributing LPs may have made them less appealing to both consumers and music producers. Despite this, LPs have experienced a resurgence in popularity in recent years, with some people valuing their sound quality and collectability.