1 For explanation of symbols, see note 1 on page 8.

2 During 6 months, 5 hours on Saturday, 50 hours a week, without reduction of pay.

3 During 3 months, 5 hours on Saturday, 55 hours a week, without reduction of pay.

4 During 5 months, 9 hours a day, 54 hours a week; during 7 months, 10 hours a day, 60 hours a week.