The number of major strikes jumped 43% to 33 in 2023, according to the official Labor Department count released Wednesday, the biggest number of large work stoppages in America in more than 20 years.

There were 462,000 workers who were on strike at some point in 2023, according to the Bureau of Labor Statistics report, and there were 16.7 million days of work lost when the number of strikers and the length of the strikes are taken into account. That’s up from only 127,000 strikers who were off the job for a total of 2.2 million days in 2022.

The greatest number of lost days of work was because of the strike by SAG-AFTRA, which represents 160,000 actors, and was on strike for about four months.

The last time there were this many strikes, or that many days of work lost, was 2000, when 39 major strikes occurred, keeping workers off the job for a combined 20.4 million days. The 33 strikes last year is roughly double the average of 16.7 major strikes a year over the course of the last 20 years.

The official Labor Department count of strikes is incomplete though, since it only tracks work stoppages involving 1,000 or more workers. And that is a relatively small percentage of strikes that take place on a regular basis.

A separate database of all work stoppages by Cornell University’s School of Industrial and Labor Relations shows that there were 451 work stoppages in 2023, up 9% from the 2022 total. So the major strikes of 1,000 or more account for less than 10% of the overall number of strikes.

When contracts are reached to end or avoid strikes, they typically run for multiple years. For example, the three labor deals at General Motors, Ford and Stellantis that ended the six-week strike by up to 50,000 autoworkers last fall will run through April 30, 2028. So many of the major strikes and contract negotiations that occurred in 2023 will not occur again in 2024. But that doesn’t mean there isn’t a chance of some major work stoppages this year.

Here’s some possible strikes that could make headlines in 2024:

Anheuser-Busch

The Teamsters union has said about 5,000 of its members at 12 breweries nationwide are prepared to go on strike on March 1 without a new contract.

The union’s most recent statement Tuesday on the state of talks said a strike “appears unavoidable” at this time. A source with the company told CNN it remains confident a deal can be reached. If there is a strike, it would be the second strike against a major brewer.

On Saturday 400 Teamsters walked out at a Molson Coors brewery in Fort Worth, Texas. But that was one of only six US breweries operated by the company, along with two more in Canada, so the company says it will not have problem meeting demand for its beer despite the strike.

Hollywood studios

Last year overlapping strikes by more than 11,000 members of the Writers Guild of America and SAG-AFTRA, which represents about 160,000 actors working in films and shows, shut down much of Hollywood studio operations for about half the year. This year could be a sequel.

IATSE, which represents 60,000 technicians, artisans and craftspeople who perform a wide variety of non-acting and non-directing jobs for feature films, television shows and streaming programs, has its contract expire on July 31.

After the deals with writers and actors last year, it could be difficult reaching a deal that would satisfy the membership of IATSE, who only narrowly approved the last contract with just 50.3% of rank-and-file voting in favor of it during a ratification vote in 2021.

Boeing

Boeing has had its share of troubles for the last five years, but labor unrest has not been one of those problems. That could end this year.

A contract covering 30,000 machinists who build the planes at its factories in Washington state is due to expire September 12. With Boeing reporting five years of losses, the total exceeding $26 billion and no end in sight to the red ink, it could be difficult for the union to get the contract it wants from Boeing with the kind of large pay increases other unions have won recently.

The start of negotiations on the new contract has already been pushed back by the latest quality issue at the company, which occurred when a door plug was expelled from the side of a Boeing 737 Max 9 operated by an Alaska Airlines on January 5, leaving a gaping hole in the plane.

Airline workers

The major US airlines all agreed to deal with the pilots unions last year that gave raises of 30% or more. Now other airline unions are demanding they get rewarded as well.

The Association of Professional Flight Attendants, which represents 25,000 flight attendants at American Airlines, has asked federal labor mediators to declare an impasse that could start the clock ticking towards a possible strike. Other unions representing about 50,000 other flight attendants are also involved in mediated talks with their members’ airlines.

And unions representing tens of thousand of other airline workers, including customer service employees, mechanics and other ground workers, are seeking contracts as well.

Labor relations in the airline industry are covered by a different labor law, the Railway Labor Act, than what covers talks at most private sector employers. There are limits on airline unions’ ability to go on strike under that law, but union officials are hopeful that President Joe Biden would let them to wield the threat of a strike as a way of getting the contract they say members deserve.