With referrer it is the same numbers I get so where are the rest of the visitors and visits?

Hi all,In the table below, out of 557 unique visitors, 121 have a referrer type specified. Similarly, out of 569 visits, 127 have a referrer type specified. Where are the rest of the unique visitors and visits?Thank you  

Hi ,On Prop6, a notable number of unique visitors are designated as 'unspecified.' However, upon examining the URL level, I've noticed that these URLs have Prop 6 assigned to a  country. Why does this discrepancy occur?  when I use evar 6, this numbers is lower but still notable However, upon examin...

Dear All,I came across a rather peculiar discovery in visitor traffic data. The presence of two or three unique visitors per unique visitor ID strikes me as highly unusual. How could this be possible? Thank you