The given line graph compares the participation of four different age groups in the gym monthly or more from 1990 to 2010, at four-year intervals. Overall, it is salient that the access to gym increased in all surveyed ages, with the most significant rise observed in the youngest category. Additionally, this 18-24 age group, despite its modest starting point, surpassed other ages and dominated during most of the surveyed time, whereas the oldest category exhibited the least interest in the gym over time.
Regarding categories with the most dramatic rise, starting at approximately 5%, the proportion of individuals aged 18-24 significantly increased, converging with the 25-34 age group, whose initial point was around 6%,at slightly over 30% in 1998. After that, while the latter continued to follow an upward trend until the end with 40%, the former peaked at around 58%, despite its trough at marginally over a half during the 2006-2010 period.
Concerning the remaining categories, individuals aged 35-44 and 45 to over experienced the roughly equal figure at merely 4% in 1990. Furthermore, these groups shared a similar upward pattern in the next sixteen years, reaching around 23% and 10%, respectively. Similarly but to a larger extent, both groups escalated, with an increase of approximately 17% for the 35-44 group and 12% for the oldest.