The number of incarcerated drug offenders has increased twelvefold since 1980.
The number of cases of salmonella infection has increased twelvefold in six years.
Prescription charges have gone up twelvefold since 1979.
I understand that they increased twelvefold between 1900 and 2000.
The twelvefold way provides a unified framework for counting permutations, combinations and partitions.
Enumerative combinatorics concentrates on counting the number of certain combinatorial objects - e.g. the twelvefold way provides a unified framework for counting permutations, combinations and partitions.
During the same period, bicycle output increased about three and one-half times, production of electric fans increased twelvefold, and the output of radios doubled.
Educational, food, and housing assistance was significantly expanded, with public-housing starts going up twelvefold and eligibility for free milk extended from age 6 to age 15.