The phrase "a tripling of reported" is correct and usable in written English.
It can be used when discussing an increase in the number of reports or instances of something, often in a statistical or analytical context.
Example: "The study revealed a tripling of reported incidents of fraud over the past year."
Alternatives: "a threefold increase in reported" or "a threefold rise in reported".
The English Bridge Union has reported a tripling of its young members over the past three years.
Last month, Blackstone reported a tripling of its second-quarter profit, thanks in part to cashing out of its investments".
However, Maternity Action, a specialist advice service, has reported a tripling of demand for its helpline (for every call it takes, it has to drop 21).
Last week another team of British-led scientists reported a tripling of leukaemia and brain cancer risk in children linked to CT (computed tomography) head scans.
Most recently, the CDC reported a tripling of fentanyl-involved deaths in the District of Columbia, Illinois and Maryland, and a more than doubling in Connecticut, Missouri, New York, Virginia, Vermont and Wisconsin.
In May, the US Centers for Disease Control and Prevention reported a tripling of the number of disease cases resulting from mosquito, tick and flea bites nationally over 13 years — from 27,388 cases in 2004 to 96,075 in 2016.
That was followed last spring by Capitol security officials reporting a tripling of threats against members of Congress -- almost all from opponents of health care reform -- in other words, from Republicans, right-wingers or people influenced by GOP TV and radio front men who personally profit from the hostile climate they generate.
This is the first study reporting a tripling of mortality with the higher CD4 count threshold for late presentation.
The report estimated a tripling of the department's budget was needed for at-risk youth services, and said there were "strong arguments" for a new and separate department.
