COUNTIF specific text on visible cells

i have a list of 164 stocks on the sheet. each has an associated sector to it. if i include all 164, i want to create a simple pie chart showing the breakdown. so total data on Column A and B, column D and E show the breakdown. im sure COUNTIF formula in column E.
easy enough.

now, lets say i want to filter some out in column B, lets say we want to remove all communications sector, or hide them. how do i get column E to reflect that and show 0, instead of 3?

thanks