In any one-year period from April 1 to March 31,a workplace that usually employs fewer than 100 workers, as referred to in paragraph (2) of Article 76 of the Act is one with fewer than 100workers,ascalculated by dividing the number of workers, in terms of worker-years, during the one year before the relevant April 1 have been employed from April 1 to March 31 each year by the number of the prescribed working days for the year concerned .