As you can see total sum is 5, sometimes error happens in your browser or between scripts loading, sending of headers etc and hit gets counted as nocookie or not counted at all. It's perfectly normal. In trade scripting such phenomenon is known as traffic loss, thats why for example you need to oversend ~ 130-135% when you have new site, so your return should be 130-135 and your trade partner see's it as maybe 120-125%....because of that traffic loss