

As read on wikipedia ( https://en.wikipedia.org/wiki/Social_Security_number ) the format only allows +/- 100k numbers per area code ( which is also limited to 999 codes? ), so over time you are forced to reuse some codes. In total the format allows 99m unique codes, and the us currently has 334mil people sooooo :')
Oh ye, our system wouldnt fit india as its limited to 500 births a day ( sequence is 3, digits and depending if its even or uneven describes your gender ). Your system seems fine to me and beats the us system hands down haha