Small businesses in 2015 saw their softest year of employment growth since 2011, according to data released Tuesday.
The monthly Paychex | IHS Small Business Jobs Index decreased to 100.37 in December. "It was a slight drop from last December and pretty flat to November," Paychex CEO Marty Mucci told CNBC's "Squawk Box."
Last year ended with a consistent downward trend since the index peaked in April 2014 at 101.26.
While December marked the 51st-consecutive month of job gains, the 12-month growth rate was slightly negative — minus 0.19 percent — with gains continuing to slow following the low point of the recession.
The Mountain region was the top-performing area, with a 12-month job-growth rate of 0.48 percent.
After a large jump in November, the pace of employment growth in the mid-Atlantic region slowed slightly in December, as it fell back to the lowest index among regions.
Service jobs, in a category as varied as repair and maintenance to personal and laundry, remains the top-ranked industry. "Service is a real positive. People are spending discretionary income now. So they are feeling a little better as a consumer," Mucci said.
Construction as well as leisure and hospitality rounded out the top three industries for small business job growth.
The index from Paychex and analytics firm IHS is based on information gathered from about 350,000 U.S. small businesses with fewer than 50 workers. It analyzes payroll data from the client base of Paychex, an HR provider.