The phrase "a proportion of which" is correct and usable in written English.
It can be used when referring to a specific part or percentage of a larger group or quantity that has been previously mentioned.
Example: "The study surveyed 500 participants, a proportion of which reported experiencing anxiety."
Alternatives: "a percentage of which" or "a fraction of which".
Fruit Shoot My-5 contains no added sugar, only naturally occurring sugars from the fruit, a proportion of which will be fructose.
Natural waters serve as habitat for a wide range of microorganisms, a proportion of which may be derived from fecal material.
So far, they have received £467m in projected bailouts, a proportion of which was given to cover penalties owed by the companies for failing to meet targets under Grayling's "payment by results" system.
Given the major use of TiO2 in many industrial and domestic applications where loss to the sewer is possible, this measured Ti was presumed to have been largely TiO2, a proportion of which will be nanoparticle sized.
Time deposits (( {mathrm{D}}_2{mathrm{D}}_{mathrm{t}} )) are longer-term deposits a proportion of which can be loaned or invested in government securities.
TRAMP mice, which predictably develop prostate adenocarcinoma, were backcrossed with gammadelta T cell-deficient mice (TCRdelta mice) yielding TRAMP x TCRdelta mice, a proportion of which developed more extensive disease compared with control TRAMP mice.
In last year's budget, the government committed an amount of money--a large proportion of which would go toward the recruitment of new faculty--that was based on the calculation of full funding for these additional students.
There is a proportion of that which is illicit finance," she said.
In doing so he highlighted the amount spent as a proportion of GDP (which stands for gross domestic product and measures the size of the economy).
Heterozygotes are readily recognisable by HRM because they form a proportion of heteroduplexes which melt differently to perfectly matched homoduplexes.
The result is a sluggish economy (a growing proportion of which is owned by foreigners); low productivity (because the manufacturing sector has shrunk to one-tenth of GDP); and static pay, as every sector except finance cuts costs to survive.
