The 2018-2019 school year is ushering in more teacher strikes across Washington state than we've seen since 1983, and the 100th strike since collective bargaining began in the early 1970s.

That's according to historical data provided by the Washington Education Association which represents teachers during contract negotiations.

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There have been a total of 104 teacher strikes in Washington state according to the WEA data. The first was in the Aberdeen School District between May 11-15, 1972.

The longest strike in state history belongs to the Marysville School District in 2003. Teachers walked out on Sept. 2 and did not return to class until Oct. 22 when union members voted to end their record-setting strike and comply with a judge's back-to-work order.

The 40-day strike was over teacher salaries and compensation for additional work days.

The longest strike in Seattle Public Schools, the largest district in the state, happened in 1985 when teachers walked the picket lines for a total of 25 days over teacher compensation and class size.

Seattle, Tacoma and Renton schools all have seen teachers strike four times since collective bargaining began.

While the 1970s and early 80s saw a large number of strikes, the 90s and early 2000s were relatively quiet.

But the current number of six school districts currently experiencing teacher strikes is the most since 1983. That number is mostly because of the newly formed school funding formula adopted by state lawmakers under the McCleary decision.