How much is much? 30%? 60%? 90%? All these are "much", while they so different

Context:

While you believe that bringing an end to religion is an impossible goal, it is important to realize that much of the developed world has nearly accomplished it. Norway, Iceland, Australia, Canada, Sweden, Switzerland, Belgium, Japan, the Netherlands, Denmark, and the
United Kingdom are among the least religious societies on earth. According to the United Nations' Human Development Report (2005) they are also the healthiest, as indicated by life
expectancy, adult literacy, per capita income, educational attainment, gender equality,
homicide rate, and infant mortality. Insofar as there is a crime problem in Western Europe, it
is largely the product of immigration. Seventy percent of the inmates of France's jails, for
instance, are Muslim. The Muslims of Western Europe are generally not atheists. Conversely,
the fifty nations now ranked lowest in terms of the United Nations' human development
index are unwaveringly religious.

-Sam Harris