The phrase "a decrease in the frequency of" is correct and usable in written English.
It can be used when discussing a reduction in how often something occurs or is observed.
Example: "The study showed a decrease in the frequency of reported incidents over the past year."
Alternatives: "a reduction in the occurrence of" or "a decline in the rate of".
We wrote to 11 previously supported organizations requesting a decrease in the frequency of appeals but received a reply from only two.
As predicted, with increasing patch perimeter, the ability of the large (dominant) fish to defend the patch decreased, as reflected by a decrease in the frequency of aggression and the proportion of the aggression by the dominant.
It has also been shown that with increasing age, there is a decrease in the frequency of variables such as stress as a trigger, photophobia, phonophobia, dizziness, throbbing, pressure, stabbing, and being forced to sleep or rest during headache attacks.
In other words, the sharp decline in the age-crime curve that occurs in early adulthood reflects both a decrease in the prevalence of offending and a decrease in the frequency of offending (Piquero et al. 2003).
Two weeks after injection, there was a decrease in the frequency of donor cells.
We constantly observed a decrease in the frequency of T cells expressing the transduced TCR already by day +5 post-infection.
Analysis of the second period shows an increase in the frequency of the SW and a decrease in the frequency of the N circulation types in spring.
The advantage of the shorter chambers was a decrease in the frequency of overlapping flies, thereby limiting the effort required for correcting tracking errors.
Thus a decrease in the frequency of clouds corresponded to a greater degree of divergence between rainforest and dry forest NDVI (Figure 3b).
The results for the end of the 21st century show a decrease in the frequency of cyclonic, W, and SW circulation types in the spring and summer months.
In summer, all models show an increase in the frequency of type NE and a decrease in the frequency of types SW and W. Furthermore, in two out of the three models, an increase is observed in the frequency of type E, along with a decrease in the frequency of the NW types.
