The lumen, abbreviation lm, is the SI derived unit of luminous flux. It is the amount of light that falls on a unit area at unit distance from a source of one candela.
... is spread out with 30.3% under the age of 18, 8.1% from 18 to 24, 29.9% from 25 to 44, 23.8% from 45 to 64, and 7.9% who are 65 years of age or older. The median ...