WASHINGTON (AP) — The number of Americans collecting unemployment benefits fell last week to the lowest level in 44 years, another sign that most workers enjoy job security.

The Labor Department says claims for jobless aid dropped by 22,000 to 222,000, fewest since March 1973. The less volatile four-week average slid by 9,500 to 248,250, lowest since late August.

Unemployment claims are a proxy for layoffs. The low level suggests that employers are confident enough in the economy to hold onto workers. The unemployment rate last month hit a 16-year low 4.2 percent.

The economic impact of Hurricanes Harvey and Irma has faded in Texas and Florida. But the Labor Department says that Hurricanes Irma and Maria have disrupted the ability of people to file claims in Puerto Rico and the Virgin Islands.