You have to look at how they obtained the data.
Whether it is through official websites, private websites, corporate databases, or some internal databases of the State Intellectual Property Office, when searching for a certain industry, it should usually be based on the classification number. For example, A63b is for fitness equipment, so you can get rough reference data.
The absence of appearance patent data only shows that the analysis of this industry is based on technology, and there is no need to analyze the number of appearances. (Unless it is an industry where appearance is also important). It all depends on the analyst's goals.
Of course, the number of exterior designs can also be retrieved through the classification number combined with a certain time zone. Of course, appearance is different from the commonly used IPC classification standards. Designs have their own classification number system. If the field is very narrow, you can also consider adding the name of the design as a keyword. For example, "bicycle" or something like that.