MUMBAI: Reliance Jio added 4.78 million customers in May, more than double of what market leader Bharti Airtel , data on the sector regulator's website showed.According to Telecom Regulatory Authority of India ( TRAI ) data, Bharti Airtel added 2.09 million customers in May while Vodafone and Idea Cellular added 1.13 million and 0.19 million customers respectively.Read More: Reliance Jio raises rates, but it’s no Dhan Dhana Dhan for telcos Visitor location register (VLR) , a key metric indicating the number of active subscribers on a network, showed that 96.87% of the users were active for Airtel, 94.02% for Vodafone, 101.17% for Idea Cellular and 75.73% for Jio The data for May by TRAI shows that Bharti Airtel continues to remain the largest operator with a market share of 23.59% with a total of 278 million customers. Jio has increased its market share from owning 9.58% in April to 9.94% in May and has 117 million customers.Idea Cellular however has seen a marginal dip in its market share from 16.69% in April to 16.62% in May end with a mobile customer base of 196 million.Vodafone has managed to maintain a status quo with a 17.86% of the wireless subscriber market pie. The company that is in the process of being merged with Idea Cellular has about 210 million wireless subscribers.TRAI data for May states that the number of subscribers opting for mobile number portability ( MNP ) increased from 277.72 million at the end of April to 283.09 million at the end of May.Also Read: ​ Airtel, Idea likely to contain revenue fall as Jio freebies end MTNL, Telenor, Sistema and Tata Teleservices have continued to lose subscribers.The total number of active wireless subscribers in May, 2017 was over 1.02 billion, while the total number of users were 1.18 billion.