The phrase "a small decrease in the percentage" is correct and usable in written English.
It can be used when discussing statistical data or changes in numerical values, particularly in reports or analyses.
Example: "The study showed a small decrease in the percentage of participants who reported symptoms over the course of the treatment."
Alternatives: "a slight reduction in the percentage" or "a minor drop in the percentage."
Anne Marie Duffy, director of qualifications at Northern Ireland's awarding body, said: "Over time results can fluctuate and this year we have seen a small decrease in the percentage of entries gaining the top grades.
Other changes will see a small decrease in the percentage reduction in payments by absent parents who may have other children living with them.
There was also a small decrease in the percentage of PISA-eligible students who had already left the education system (from 2.1% in 2000 to 1.5% in 2009).
He said the recent controversies, combined with the unusual heavy snowfall in Britain last winter, may explain why there has been a small decrease in the percentage of people who believe that the climate is changing.
Further analysis of the spleen and lymph nodes shows similar percentages of CD8 T cells and a small decrease in the percentage of CD4 T cells in both of these organs (Figure 1c).
Interestingly, treatment of ERBB2-positive tumors with the EGFR/ERBB2 inhibitor lapatinib led to a small decrease in the percentage of breast CSCs [ 1].
This led to a very small decrease in the percentage of bases covered.
These mice were nearly twice as heavy as the control mice, and their body composition differed by a significant increase in bone density and a small decrease in percentage of body fat.
Those risks outweighed the drugs' benefits -- a small decrease in hip fractures and a decrease in colorectal cancer.
Patients with suboptimal HDL-C and TG had the smallest decrease in the percentage of patients not receiving lipid-modifying therapy.
In HIV-1-infected patients harbouring the M184V mutation (M184V), lamivudine monotherapy leads to a smaller decrease in CD4 percentages (CD4%) than treatment interruption, possibly due to the reduced fitness of the mutated virus.
