“To safeguard privacy, we exclude from these files certain names that would indicate, or would allow the ability to determine, names with fewer than 5 occurrences in any geographic area.”
In other words, names with less than 5 occurrences in a year would be excluded, so you won’t even see them on the graph. But it doesn’t always mean there were 0 people born that year with that name.
TNF uses a third party library to render the graphs. Because of the way the library was designed, years with no numbers of both genders will be omitted entirely. So far, I haven’t figured out a workaround.
The SSA releases yearly data the following year–so 2020’s info would be out in 2021. If you’re not seeing any numbers for the previous year, it could be because they haven’t released it yet. 2019’s info was released in March, I’m assuming that’s normally when they release this info.
All of the names from the SSA’s site seem to have any diacritics (ex. acute accents, etc) removed. TNF’s records include the diacritics however.