The total number of students who sat for the exam in 2019 also substantially declined from 2039 in 2018 to 1970 candidates last year.
The Ministry of Education revealed this trend while announcing the release of TSC results to schools.
A standard pass is English plus three best subjects at Achieved Grade.
The best performing school is Tonga High School with 86% pass rate. Tonga High School also had the most consistent improvement rate since 2016.