You dont get population close to 12 crores by a constant leakage which takes place on every border in the world. There has to be a big hole...there has to be a deliberate effort to do that.... these people contantly flowed in stayed in bengal gave a vote and then trickled into other states....its not so easy.....dealing with so huge a number...there has to be a deliberated..well thought out plan That Is My Point!!!! If you have handled any marriage party then you would know what it takes just to handle couple of hundreds...... so I hope you get my point