Fractional Conversion Numbers??

Can anyone please explain why the second column (Conversions) does not display integer values?

A person clicks on one of your advertisements and accesses the website.

Subsequently, they return to the site through a link on Facebook.

Later, they visit again by searching on Google.

Finally, they make a purchase, thus completing the conversion.

Would you prefer to attribute credit for the purchase to paid ads, social media, or organic means? Alternatively, do you believe that each touchpoint should receive a share of the credit, represented as a fraction of the overall conversion?