U.S. services companies in October grew at the best rate in more than a dozen years.

The Institute for Supply Management said Friday that its services index rose last month to 60.1 from 59.8 in September. Any reading above 50 signals expansion. The October reading was the biggest since August 2005. The services sector has reported growth for 94 consecutive months.

The strength in the services sector is emblematic of a U.S. economy that looks increasingly healthy. Employers added a robust 261,000 jobs in October, the Labor Department said Friday. Economic growth climbed above an annualized level of 3 percent for the past two quarters — and appears to be solid for the final three months of 2017.

There's no question that the U.S. economy appears to be stronger than it was a year ago, said Anthony Nieves, chair of the ISM non-manufacturing business survey committee.

"The question that remains is how sustainable is this," Nieves said.

For services companies, measures of business activity and employment improved last month. But a measure for new orders — while still positive — weakened slightly.

There were 16 sectors reporting growth last month, including construction, retail, finance and insurance and accommodation and food services. Two industries reported contraction: education and the arts and entertainment sector.

Private service-sector workers account for more than 70 percent of American jobs. The improving conditions point to continued economic growth in the months ahead.