Exhibit 6.12 Contribution of Human Capital, Physical Capital, and Technology to Differences in PPP-adjusted GDP per worker Country PPP- Average Percentage of PPP-adjusted (1) adjusted Years of U.S. Physical GDP per GDP per Schooling Capital Stock worker If worker in (3) per Worker in Technology 2014 2014 Were at U.S. (2) (4) Level (5) United States 112,517.30 13.18 100.0 SAME United Kingdom 83,611.74 12.24 86.9 102,902.90 Spain 88,944.35 10.27 81.2 91,985.66 South Korea 67,246.82 12.05 52.6 86,293.01 Mexico 38,661.51 8.79 21.0 54,766.86 Brazil 28,935.31 7.89 13.4 45,215.59 China 21,394.03 7.95 10.5 41,837.58 India 13,260.64 5.24 2.8 24,056.65 Pakistan 15,492.71 5.02 2.2 20,321.71 Ghana 7,497.48 7.00 1.7 21,407.27 Dem. Rep. of the Congo 3,757.44 3.66 1.6 16,651.50 Source: Data from Penn World Table (Alan Heston, Robert Summers, and Bettina Aten, Penn World Table Version 7.1)