To count the number of tetrads for each taxon, you add a ‘distinct’ clause to the grouped query. In the example below, the number of tetrads for each taxon within Kent (vice-counties 15 and 16) since 1987 is listed.
![](https://docs.bsbi.org/media/pages/ddb/searching/example-searches/taxa-vc-tetrads-since-year/24f256eb45-1700063519/screenshot-2023-10-10-at-08.57.25-600x.jpg)
Monad can be substituted instead of tetrad within the ‘distinct’ clause.