The NASUWT teaching union alone secured £12.6 million in compensation last year, almost a 20% increase on the 2010 figure of £10.5 million.
This is for claims including personal and criminal injury, unfair dismissal and employment cases.
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The group paid tribute in the Mamayev Kurgan memorial park.
A nine-year-old schoolgirl was among the victims around the city of Osaka.
Supporters are still arriving in the city.