All variables included for mapping are divided into 5 groups: bottom 40% districts, next 20%, next 20%; next 10% and top 10%. Only for rice and wheat we have 6 groups. Bottom 20% next 20%, 20%, 20%, next 10% and top 10%.

For maps using apportioned data the groupings are based on 1966 data for area and production (1995 for soybean, sunflower, safflower and castor) and 1995 data for yields. Thus, the change over time from the base year to 2015 in area, production or yield can be visualized. Additionally, the share of districts across the groups in any given year is given below the map for comparison with base year shares. For example, if the highest group is 15% in 2015 implying the number of districts in this group increased from 10% in the base year to 15% and so on.