The phrase "a falling number" is correct and usable in written English.
It can be used in contexts where you are discussing a numerical value that is decreasing or declining over time, often in scientific or statistical discussions.
Example: "The study revealed a falling number of participants in the annual survey, raising concerns about engagement levels."
Alternatives: "a decreasing figure" or "a declining number".
The vast majority of the Islands' population live in Port Stanley, the capital - with a falling number in the surrounding 'Camp' wilderness.
Saunders predicted a lot more gaps as the high street struggles with a falling number of visitors with a decreasing amount of money in their pockets.
Holiday firms have been hit by fears of terrorist attacks, and concerns about a falling number of UK tourists, thanks to the weakness of the pound following the Brexit vote.
There are recurrent themes causing the crisis: more people are coming to A&E; a falling number of doctors want to work there because of the pressures involved and the poor work/life balance; and hospitals are increasingly full – resulting in bottlenecks that back up into the emergency department.
Confidence has slipped in Scotland's small businesses, with evidence that a falling number of companies are planning to invest.
The absence of statistical significance in group 5*104 evaluating PCI and "area of tumor adhesion" possibly can be traced back to a low falling number because of the dead of an animal in this group.
The results will be welcomed by the Games organisers who adopted "Inspire a generation" as their motto, against a background of falling numbers of women taking up sport.
The CEM warned the government three years ago that there was a problem with falling numbers of staff, but no concrete solutions emerged.
The current spike in totoaba fishing was apparently triggered by falling numbers of a similar fish caught in Chinese waters.
Yet another year of falling numbers reveals a dangerous complacency in making education accessible to parents, carers, workers, and anyone else who cannot feasibly study full-time".
General health, use of a walking aid, falls, number of medications, mobility or self-care problems, anxiety or depression, showed no association with participation.
