 ::The simplest way is to rename the section to make that clear. Incidentally the idea that there was a long term decline in turnouts from the 1950s is dubious. Turnout at General Elections from 1922-1997 fluctuated between 71% and 77%, the elections of 1950-1951 were exceptions to that. Turnout slumped in 2001 and has started creeping back up but it's too early to identify a trend from that.   