(This exercise was inspired by Noe Calle's post and the following corrections and suggestions from GuideDogSaint and Jim G, many thanks to them.)
The graph shows the change in male and female gym memberships between 1990 to 2010. While female gym membership remained respectively steady, male gym membership fluctuated dramatically over the years.
Let's look at the figures in more detail. The male gym memberships were just over 2,000 in 1980, twice the memberships of female that year. Since then, both male and female memberships have grown rapidly until 1995, when both male and female numbers doubled to 4,000 and 2,000 respectively( not sure if I use the right adverb here).
After that, the male number dropped steadily to around 1,500 in 1995. This compares with the female number, which surpassed the male number and rose to almost 3,000 by 1995.
Afterwards, male memberships experienced a rapid growth and fall. It rose to a record of 5,000 in 2005 from roughly 1,500 in 1995, and then dipped to a low of just over 500 in 2010. Whereas, the female membership fluctuated slightly up and down, ranging between 2,000 and 3000. It reached 2000 by 2010, 4 times the memberships of males by that year.