Even after excluding the rarest elements, it is sometimes useful to display sample sizes on the final figure. This can be done using the labels tab on the layer properties:
Check the box marked 'label features in this layer'.
Set the 'label field' to 'n' and click 'expression'.
The expression box should already display '[Gomolava$.n]'. Type '"n=" + ' before this, including the double quotation marks, and click OK twice.
The labels should appear. In this case they are clearly not practical, so remove them by unchecking the 'label features in this layer' box. In other circumstances you might want to keep some labels, in which case it is possible to use a query to limit which features have labels displayed.