Ignore this box please.
Search syntax
s:d     sort by date
r:uk     uk region
site:     domain search
\ search     first result

r:n    turn off region
!a search     search amazon
site:uk     uk pages
f:     find files
t:     within title
b:     within body
More explanation...
Calculator
20000000 / 18000000000 * 100 = 0.111111111111111