For example, half of all Chinese now live in a city (up from a third in 2000). And there are double the number of migrant workers (farmers who move to cities to find work) than ten years ago. China's overall population is growing, but only very slowly. Worryingly though, the percentage of elderly citizens has grown from 10% to over 13% and there are 12 boys for every 10 girls. So some problems in store for the future, perhaps.