Currently, Nozzle only shows search volume for keywords you rank for. Unless you do this.
You can see the search volume for all your keywords by changing the Rollup dropdown to Domain and then selecting google.com (or some other Google TLD) as the domain you want to examine.
This works because Google has some kind of result on very nearly every SERP, so when you change the rollup this way, it will get around the limitation of your own rankings and let you see the search volume for your list of keywords.
This approach will work in either the Overview dashboard or the By Keyword dashboard.