It has been a while that Google stops providing keyword DATA to webmasters so if you want to know the exact terms which drives traffic to the website and provide you conversions then forget about it Google is no more going to provide the data and by the time this %age of “not provided” is going to increase instead of decreasing.
But you can still have a bit of an idea of what keywords people might be coming from by looking in to top visited URLs and then compare it with the keywords that you are targeting on those pages. Check the ranking of the keywords in Google and you will have an idea of which keywords are working for you and which aren’t!
Hope this helps!