The country added a whopping 51.18 million mobile users during the quarter ended 30th June this year, taking the wireless subscriber base to 635.51 million. Telecom Regulatory Authority of India (TRAI) said in a statement that the total telecom subscriber base (including wireline and wireless)touched 671.69 million for the quarter ended June this year from 621.28 million in the quarter ended March, registering an increase of 8.1 per cent. The statement added that the overall tele-density (number of telephones per 100 people) for the quarter ended June reached 56.83.