Many governments publish this sort of information online, which means you'll want to get familiar with official government URLs and a bit of advanced searching in your search engine of choice.
Using Google as an example: Looking for the annual production rate of corn syrup in the United States? We know American governmental website URLs end in .gov, so searching "annual corn syrup production site:.gov" will search only websites that end in .gov, which will give you more reliable results than searching everything on the web.