It goes up by 15 percent,对于所有事物都是如此and you have a 15 percent savings你还能节省on the infrastructure.15%的基础设施经费This, no doubt, is the reason这无疑就是why a million people a week are gathering in cities.城市每周新增一百万人口的原因Because they think that all those wonderful things --他们觉得那些美好的事物like creative people, wealth, i