The phrase "and a decrease in the number" is correct and usable in written English.
It can be used when discussing statistical data or trends, particularly in contexts where you are describing changes in quantities or figures.
Example: "The report highlighted an increase in sales and a decrease in the number of customer complaints."
Alternatives: "and a reduction in the number" or "and a decline in the number".
In contrast, tumors presented a denudation of capillaries accompanied by transient increase in permeability and a decrease in the number of tumor vessels17.
In 2007, the government introduced compulsory parent councils – bodies that were meant to compensate for the introduction of sponsor and commercial governors and a decrease in the number of parent governors.
Weaning was also associated with a decrease in crypt density, an increase in mytotic index and a decrease in the number of goblet cells.
Dramatic increases in rates for liability insurance since last season - more than 400percentt in some cases - and a decrease in the number of agencies willing to underwrite ski areas have cut deeply into the profit margin of many operations.
The combination was studied extensively in African Americans with heart failure, many of whom experienced increased survival and quality of life and a decrease in the number of hospitalizations.
From the end of the Pleistocene through the Holocene, both groups of faunas show an increase in the number of inhabitants of partly forested landscapes and forests, and a decrease in the number of open landscape species.
When feeding space allowance was increased, we observed an increase in the time a cow spent feeding and a decrease in the number of feeding bouts in relation to the total time feed was available, particularly in subordinate cows.
In rat bone, the absence of mechanical load results in a reduction in bone formation, inhibition of longitudinal growth, and a decrease in the number of osteoblasts and osteoprogenitors in cancellous bone.
Environmentalists and birders are tracking the crab population as well, because a huge surge in the number of crabs collected for bait in the last decade, and a decrease in the number of the shorebirds that feed on them -- red knots in particular -- have caused alarm.
The corporation shares many of the same woes as the rest of the hospital industry -- reduced reimbursement rates from managed care companies, smaller government subsidies and a decrease in the number of patients, who now get more of their care in outpatient settings.
Other reasons it gave were improved screening of complaints to eliminate those that may not be violations and a decrease in the number of investigators covering more than 100 million workers — to 732 in the 2007 fiscal year from 945 in 2001.
