The official parity calculation was based on the ratio of farm prices to nonfarm prices between 1910 and 1914, the most prosperous non-wartime years for farmers in American history.
The local system of ratings notches isn't directly comparable with international systems, but the ratio of upgrades to downgrades is now heading towards parity, from two or more a year ago.
Net Enrollment Ratio in primary education had increased from 58% in 1999 to 76% by 2010 and the Gender parity index from 0.85 to 0.93 over the same period of time.