IF GNP per capita at constant prices for Liechtenstein a microstate of 29,000 people located on the Rhine River between Switzerland and Austri is US$555 and US$560 in 2011 and 2012 respectively, the real economic growth from 2011 to 2012 is ?
A. 5%
B. 0.901%
C. 0.090%
D. 0.991%