Filtering by year seems to be bugged

not a serious issue but a bit annoying.
When I filter the 5 rupees page by year "1947-2020", it doesn't include the ones with brackets around the year.
In this picture where I haven't filtered it by year, the third coin ("World of Work")'s year has brackets around it.

On the same page, I added the filter by year and it removed the third coin, but it shouldn't have because 1994 is between 1947 and 2020.

You can also see that the number of results has changed drastically despite all of the coins being between 1947 and 2020. All of the missing coins have brackets around the years.

Hello,

The filter "Year" stands for the year visible on the coin. Many of these commemorative coins are marked as non dated (in the list of search results, the year is visible between brackets). To filter based on the date the coin was issued, independently of the date visible on the coin, you can use the filter "Gregorian date" instead of "Year".