Let us now decompose the MLD inequality measure among the three groups that have been identified. The within-subgroups inequality represents on average 65% of total inequality and this proportion does not vary much over time, except for the last period 1996. The within-subgroup inequality increased from 1979 to 1992 and then decreased, while the between-subgroup inequality increased sharply from 1979 to 1992 and decreased sharply after that period to reach a level comparable to its initial value (see Table 7).