The phrase "a slight decrease in the proportion" is correct and usable in written English.
You can use it when discussing statistical data or trends that indicate a small reduction in a specific ratio or percentage.
Example: "The latest report shows a slight decrease in the proportion of students passing the exam compared to last year."
Alternatives: "a minor reduction in the ratio" or "a small decline in the percentage."
There was a slight decrease in the proportion of pupils getting an A*, down 0.1 percentage points to 6.7%, but wide variations in individual subjects, with the proportion of teenagers getting at least a grade C in maths rising by almost five percentage points, to 62.4%.
A slight decrease in the proportion of blood meals from deer occurs in late September (Fig 1a) which may correspond to maturation and mobility of fawns, decreasing their susceptibility to attacking mosquitoes.
Similarly, a slight decrease in the proportion of deleted mtDNA was also observed in the tumour tissues of the female HCC patients.
A slight increase was observed in the proportion of births to First Nations and a slight decrease in the proportion born to the Other group, but perinatal mortality rates declined for both groups over the 20-year period.
Trypan blue staining revealed that in all cell lines, most of the cells on each culture plate were viable at 48 and 72 hours, although there was a slight decrease in the proportion of viable cells at 72 hours (data not shown).
This is important information as compared to a very recent report on long-term anti-TNF treatment over eight years, where we had observed a slight increase of BASFI levels in comparison to previous years, a finding which also contributed to a slight decrease in the proportion of patients achieving partial remission at the end of that study.
In Spain, the study conducted by Roman-Viñas et al [ 40] observed a slight decreased in the proportion of sedentary leisure time activities for males (from 50% to 45%) and females (from 67%to63%3%).
Conversely, in most progressive tumours the proportion of vimentin-positive surface did not change, except a slight decrease in the sunitinib monotherapy group.
It shows a slight increase in ethylene yield and a slight decrease in the butylene yield.
A slight decrease in the crystallinity degree (3% to 5%) occurs in these samples.
A slight decrease in the mean invasion rate was observed in the presence of plasminogen.
