Fraction of the sky obscured by clouds when observed from a particular location

Fixed number that has received a name

Ratio between the useful output and the input of a machine

Number of bits that differ between two strings

index number (scaled 0–1), and near-global dataset on several dimensions of academic freedom in different countries, published by Global Public Policy Institute since 2020 (index structure described in 2017)

Number of disease cases in a given population at a specific time

Ratio between net income and investment

Dimensionless quantity that characterizes plant canopies

Number of times a given event occurs per photon absorbed by a quantum system