The phrase "a substantial proportion are" is correct and usable in written English.
It can be used when discussing a significant part of a group or category in relation to a particular characteristic or condition.
Example: "In the survey, a substantial proportion are in favor of implementing the new policy."
Alternatives: "a significant percentage are" or "a considerable number are".
Data controllers accumulate more and more data on people, of which a substantial proportion are personally identifiable and hence sensitive data.
Men between the ages of 21 and 30 are most likely to be targeted, but a "substantial proportion" are aged 11 to 20 and there have been victims as old as 82.
The contention that contemporary Bengali Muslims are all descended from lower-caste Hindus who had converted to Islam, then, is clearly incorrect; a substantial proportion are descendants of Muslims who reached the subcontinent from elsewhere.
A substantial proportion are dedicated for technology investments.
As it happens, that's already true for the majority of people on the program ― and of that small percentage who are not working or seeking work, a substantial proportion are busy caring for relatives, according to studies.
(A ) Most NMIs are associated with known protein-coding genes (left) but a substantial proportion are located within intergenic regions of the genome (right).
Some portion of this land-use change is probably attributable to agricultural intensification on formerly swidden agriculture lands; however, a substantial proportion is from new forest loss.
Results: A total of 30 and 102 proteins showed significant deregulation between normal pancreas when compared with chronic pancreatitis and pancreatic adenocarcinoma, respectively, and although a substantial proportion were found similarly dysregulated in both chronic pancreatitis and pancreatic adenocarcinoma, several proteins were identified as potential disease-specific markers.
Although some 32000 traps were placed, a substantial proportion were lost or damaged.
In addition, a substantial proportion was offered treatment with carbamazepine, flunarizine, antidepressants or alternative treatments.
A majority of the victims were registered to be from Central Thailand (57.1%) with a substantial proportion being from Northeastern Thailand (26.1%) and smaller amounts from other parts of Thailand.
