The number of pay TV subscribers is likely to top 20 million by 2011.

According to the Media and Future Institute, the number of households that have subscribed to cable, satellite broadcasting or other pay TV services will grow an average of two-point-three percent annually to amount to some 21-point-four million by 2013. As of this year, the number of such households stands at 19-point-four million.

The institute forecast the number of households that have IPTV services, or Internet Protocol TV, will rise to four-point-seven million by 2013 from this year’s two-point-two million. The number of households with digital cable services will jump to five-point-two million by 2013 from the current two-point-four million.

Meanwhile, the number of households with analog services will shrink to some nine million in 2013 compared to this year’s 12-point-three million.