First, save your $_SERVER['HTTP_REFERER'] info, and look for "Bots".
You might only have 50% human traffic. I have my own sites with as high as 65% Bot traffic.
20160107135124, /index.php, 66.249.66.37, , ^ Mozilla/5.0 (iPhone; CPU iPhone OS 8_3 like Mac OS X) AppleWebKit/600.1.4 (KHTML, like Gecko) Version/8.0 Mobile/12F70 Safari/600.1.4 (compatible; Googlebot/2.1; +
Googlebot - Search Console Help) |66.249.66.37,US,United States,CA,California,Mountain View,94043,America/Los_Angeles,37.42,-122.06,807