The Little Mermaid is a subtheme of Disney that was introduced in 2017 and currently consists of 6 sets. Most sets were released in 2018 which accounted for 2 sets. As of today, the average annual growth of all the sets in Disney The Little Mermaid is around 8.5% per year.
LEGO Disney was is a rebranded theme from the Disney Princess line in 2017 and licensed from the Walt Disney Company. Sets in the theme use standard System LEGO although most of the Disney Princess sets use minifigures like the Friends mini-dolls. These sets are mostly designed for girls aged 6 to 12.