Brand Research Help - Google Organic Keyword Searches

Hi, just doing some research on some brands I plan on selling. The majority of these brands don't have competition and all rank as the first result on the first page of google. All the ranked pages below the first result are mainly the brands social media pages and the odd blog that has posted about said brand. Most of these brands will be fairly easy to rank for organically and I think I can rank as the second result on the first page, possibly even outranking some of the brands for the first result. My question is, how much traffic, or what percentage of traffic does the second ranked webpage/result on the first page of Google normally get?