CCP recently announced a growth of 7-7.5% from now onwards, if you add population growth of 1% then per capita growth is 6 to 6.5% every year. Also considering 7-7.5% growth is sustainable by maintaining a 5% inflation, it is possible. But if you want inflation back to 3% then GDP growth will be lower with lesser govt spending in the long run. We are not even talking about competition from other countries in manufacturing. So if you want to go from $5000 now to $20000 in 2020 then your per capita growth should be much higher than it is now. The 10% 'GDP growth that you were achieveing would have done the trick if the same policy was followed. But with 7%growth per capita cannot reach $20000 with today's exchange rate.
According to current statistics your per capita cannot quadruple in 10 years because it does not have 10% growth that is required. At your current per capita growth you will quadruple from today only in 2025. So your effective per capita income will be around $15k in 2020.
Maintaining a 5:1 exchange rate is not possible till 2020 either. You will have to equalize your currency with the Euro or Dollar if you want the Yuan to be traded internationally. Equalizing will mean Chinese per capita in nominal terms will exceed the US per capita by 2020 which is awesome for chest beating but not good for economy. That's why I suggested a 50% decrease in exchange ratio by 2020 to 2:1 or 3:1. But real GDP will give a different picture.
Also you cannot take past growth as a measure for future growth. In 10 years the US per capita has doubled from $22000 to $48000 today. But will that happen again by 2020? Also you will have to start printing less money in the future, especially if Yuan is still set to depreciate. So reaching 100Trillion RMB is not easily achievable without affecting inflation.
During 2000-2010, CHinese economy avearge growth is about 11%, with a average inflation of about 4% . it makes China's GDP increase from 8.9 trillion RMB to 39.7 trillion RMB. The nominal growth totaled 450% during the 10 years(2000-2010) .
In the coming decade(2011-2020),even if CHinese economy were to grow only 6% and its average inflation were 4%, CHina's GDP in 2020 would still be 105 trillion RMB. . The nominal growth will total 265% during the 10 years(2011-2020) .
Furthermore, if Chinese economy is to grow 8% and its average inflation is 4%( I think it is quite possible), then CHinese GDP in 2020would be about 128 trillion RMB. that is 25.4 trillion USD( if RMB/USD exchange rate is 5:1). The nominal growth will total 322% during the 10 years(2011-2020) .
Frankly speaking, I think that the real average growth of Chinese economy might be between 6%-8% during 2011-2020.
Thus, it is quite possible that China's GDP might be between 105-128 trillion RMB(21-25.4 trillion USD,if RMB/USD exchange rate is 5:1 ). And China's per capital nominal GDP might be about 15-20K USD in 2020.
Of course, it will be possible that the per capital GDP all over the world will be measured not by USD,but RMB in 2020.