Number of the seller in a Shop

At the beginning of the year, one of the female workers left the job and a male joint the shop. As a result, the number of male and female became equal. After few days, a male worker left his job and a female joint the shop. At this stage, the number of male and female workers became as the same of the beginning of the year. Recently, one the male worker left the shop and joints another female. Now the number of female workers became twice then the male workers. What was the number of the male and female workers separately at the beginning of the year?