Musicians' copyright has been extended from 50 to 70 years.
The age range has been extended from 12 to 16 years.
In addition, the period over which credits could be carried forward was extended from three years to five.
In 1851, the course was extended from two to three years.
A 1954 constitutional amendment extended their term of office from two years to four.
Voters were asked whether they approved of extending the term from three to four years.
It would also extend from five to seven years the usual period required for promotions.
One extended the probationary period for new teachers from three to five years.
In 1955, a revision of the 1922 law extended the copyright term from 30 to 50 years.
The Commission has already agreed to extend the period from 3 to 5 years.