A widening gap between births and deaths has put Japan in a demographic squeeze, with fewer people to replace retiring workers and support them as they age. According to the latest reports, Japan has 512,000 fewer people this year than last. That’s a drop of more than the entire population of the city of Atlanta.Births in the country — which are expected to drop below 900,000 this year — are at their lowest figure since 1874, when the population was about 70 percent smaller than its current 124 million. Japan is not the only country having to cope with a shrinking society. It’s not even the country with the lowest birthrate: That title goes to South Korea. And other countries — including China and the United States — also face declining birthrates, which could spell trouble down the road. But Japan is the world’s grayest nation: Almost 28 percent of its residents are over 65.