After centuries of a surplus of women in Sweden\'s population, the country is expected to have a male majority in four years, a research institute says. The SCB institute forecasts the country will have a male surplus of 4,700 by the end of 2015, the Swedish news agency TT reported Sunday. Although boy births outnumber those of girls, men have traditionally died younger because of wars, hard work and unhealthy lifestyles, the institute said. However, as men and women\'s lifestyles become more similar, that difference in life expectancy has shrunk. Thirty years ago, the average lifespan of women was 6.4 years more than men\'s. Today it\'s 4.7 years longer and in another 30 years it\'s predicted to be just two years. This, combined with an influx of mostly male immigrants from Africa, the Middle East and the former Yugoslavia, is predicted to tip the male-female balance from a female surplus of 2,225 people on Dec. 31, 2014, to a male surplus of 4,700 on Dec. 31, 2015, the SCB institute said.