where ⟨...⟩ represents the statistical average over the period studied. The correlation coefficients Cij have values ranging
from −1 to +1, where −1 and +1 mean that two currencies, i and j, are completely anti-correlated and correlated,
respectively. If Cij = 0 the currencies i and j are uncorrelated. The coefficients Cij form a symmetric N × N matrix with
diagonal elements equal to unity