The phrase 'declining group' is correct and can be used in written English.
It is typically used to refer to a group of people or things that show a decrease in numbers or influence over time. For example, "The number of farmers had been steadily declining for the past decade, leaving many in the declining group unable to make a living."
Two categories of cancer patients were identified: those in whom the initial measurements of serum albumin or cholersterol, taken soon after diagnosis, were declining (Group I), and those who showed such a decline as they entered an advanced or terminal phase (Group II).
We're told of a 99.9% decline in numbers - the fastest declining group of birds in the world.
These large pterosaurs were the last representatives of a declining group that contained 10 families during the mid-Cretaceous.
During the trial we did not adjust population density caused by declining group size.
Our findings also indicated that the declining group maintained their step counts through household activities.
Six women completed the open-ended question at the end of the ARQ: 2 participants and 4 in the declining group.
Vultures are one of the fastest declining groups of animals in the world.
Oil and gas issues led the declining groups, with a plunge of 16percentt, led by the collapse in energy prices.
Barn swallows and other birds that eat flying insects – aerial insectivores – are among the fastest declining groups of birds in North America, according to the 2014 State of the Birds report.
The HABC-Monitor cognitive subscale significantly separated the improved group from the declined and stable groups but did not separate the declined group from the stable group.
The HABC-Monitor functional subscale significantly separated only the improved group from the declined group, and showed marginal ability (P = 0.058) to distinguish the declined group from the stable group.
