What does this mean?

Use the drop down menus in the upper left corner of the dashboard. You can choose between movie or TV show titles. Once you find one of your choosing, you can see when it was added to Netflix and how many seasons were added (for TV shows), its release year and rating, and a brief description. The TV rating bar graph exhibits the number of titles added between 2004 and 2019, and the different rating categories. TV-MA may include (but are not limited to) heavy cursing, graphic Violence, and/or nudity. TV-MA holds the highest ranking at 2,026 titles added between '04 and '19. TV-MA can simply be an advisory to prevent young children from being accidentally exposed to mature content, thus acting as a cushion for artistic freedom. The high number of TV-MA titles on Netflix can be attributed to the following user statistics:

• In a study of users above 18 years old, ~ 75% of users are aged between 18 to 34 years old as of mid-2021, compared to just 44% of those aged 65 or above. Millennials account for a third of its subscriber base, Generation X accounted for its second-biggest share (26%), while 22% were baby boomers (Source: Statistica).
• In a 2019 study of UK residents, only 46% of Netflix users have young kids between 0 - 9 years old (Source: Ampere). This means that the other 54% of UK residents had children 10 or older, or do not have kids at all.

Also accounting the fact that users must be 18 years or older to register for a Netflix account, the majority of Netflix users are adults without kids, which may attribute to the higher amount of mature-rated content on the platform.