When was Hyderabad added to the metropolitan cities list?

Hyderabad is an Indian metropolitan city with a population of 4.07 million. The Census Commission of India defines a metropolitan city as a city with a population over 4 million. Therefore, Hyderabad became a metropolitan city when its population reached 4 million. This was estimated to be sometime during the year 2009. So Hyderabad was added as a metropolitan city in 2009.