The phrase "diminution in the number of" is correct and usable in written English.
You can use it to refer to a decrease in the amount of something, such as "There has been a diminution in the number of tourists visiting the city since the pandemic began."
Those of us old enough to recall the comprehensive news coverage of the Telegraph in the 1950s and 60s will wonder, yet again, whether it means a diminution in the number of stories carried by the paper.
For the TMT, a diminution in the number of perseverations was observed after training in both groups (main effect of Time, Table 4).
A diminution in the number of species in those aquatic communities linked to high salinity had been noted by Peralta and Fuentes (2005) and Scheibler and Ciocco (2011) in their investigations performed exclusively at the Carilauquen spring.
And in the three months since the federal benefits stopped, there has been no real diminution in the number of long-term unemployed and no notable change in the pace of the unemployed finding work.
Although not systematically, a diminution in the number of sudden fluorescent concentration or reversely, of fluorescent local concentration leaving the evanescent field is indeed observable upon nocodazole treatment, in TIRF microscopy image series.
We also noted a diminution in the number of expected heterozygous animals (P < 0.0001).
Diminution in the numbers of epididymal sperm after 10 and 20% of calcium chloride treatment was more drastic (p < 0.001) in respect to other dose treatment (Table 1).
CENP-F −/− cardiomyocytes showed a marked decrease in the number of intercalated discs and a diminution in the accumulation of disc-related proteins.
The decrease in the number of clinical cases may have been caused by diminution of the V. parahaemolyticus O3 K6 pandemic group in regional seafood.
In contrast to a fourfold diminution in HHV-7 positive cells after treatment, there was only a twofold reduction in the number of BDCA2 positive plasmacytoid dendritic cells.
A decrease in the number of AdipoR receptors is the main adiponectin sensitivity influence regulating factor, and it may induce diminution of adiponectin effects (e.g., reduction in tissue insulin sensitivity observed during T2D) [ 30, 63, 64].
