This database was built using data from BEFORE Google required active ad accounts to get good keyword data & before they started blending data together for similar terms. Even if you set up an AdWords account and spend significant sums of money with them, they may require you to run your ad campaign for 3 or 4 months straight before they will show reasonably precise data instead of exceptionally broad data ranges.
Can't go wrong with the Google Keyword tool, SEMRush and Google Trends. The Keyword tool for volume estimates, SEMRush to see what keywords competitors are ranking for/targeting, and Google Trends to make sure the traffic is actually coming from countries I'm trying to target. Gives a relatively accurate picture of when to expect traffic spikes and seasonality insight.
More on this How to Do Keyword Research with SEMrush Keyword Magic Tool Post Maria Raybould SEMrush Toolkit for SEO Ebook Mar 16, 2018 Intent research: Confirming your keyword intent assumptions with Google ads Webinar recorded on  Sep 20, 2018 Of course, knowing where to start can be difficult. Below you'll find the five best SEO keyword research tools I recommend for startups to begin a well-rounded keyword foundation for your campaigns.
In a nutshell, Long Tail Pro helps you quickly find keywords in bulk based on a seed keyword that you input.  In addition to returning hundreds of related keywords, the tool also shows search volume (monthly search volume), advertiser bid, number of words, rank value, and my favorite Keyword Competitiveness (helps you judge the competition and keyword difficulty).