SINGAPORE - About 30,000 work pass holders who are of Chinese nationality left Singapore over the Chinese New Year break and have not returned, said Manpower Minister Josephine Teo on Sunday (Feb 2). These workers, who would be required to go on a 14-day leave of absence when they return to Singapore, make up less than 1 per cent of the work force here, said Mrs Teo. The figure does not include Singaporeans who have recently travelled to China who will also need to go on a leave of absence when they return. They can go back to school or work only after 14 days, provided they are well.