CREATE TABLE table_204_277 (id DECIMAL, "region" TEXT, "country" TEXT, "location" TEXT, "size  ( m ) " TEXT, "payload  ( metric tonnes ) " TEXT, "degrees of freedom" DECIMAL, "x horiz disp  ( mm ) " DECIMAL, "y horiz disp  ( mm ) " DECIMAL, "z vert disp  ( mm ) " DECIMAL, "x horiz vel  ( mm/s ) " DECIMAL, "y horiz vel  ( mm/s ) " DECIMAL, "z vert vel  ( mm/s ) " DECIMAL, "x horiz accel  ( m/s2 ) " DECIMAL, "y horiz accel  ( m/s2 ) " DECIMAL, "z vert accel  ( m/s2 ) " DECIMAL, "max freq  ( hz ) " TEXT, "details checked" TEXT)

which is the least region charted on this chart
SELECT "region" FROM table_204_277 GROUP BY "region" ORDER BY COUNT(*) LIMIT 1
SELECT "region" FROM "table_204_277" GROUP BY "region" ORDER BY COUNT(*) NULLS FIRST LIMIT 1