C20000-C20999  5 1/2" x 19 1/4"

         C21000-C21999  5 1/2" x 19"

1914-18  1-2-digit  5 1/2" x  7 3/4"  (Verify 1917-18)
           3-digit  5 1/2" x 10 1/2"
           4-digit  5 1/2" x 13 3/8"
           5-digit  5 1/2" x 16"      (1914)
           5-digit  5 1/2" x 16 1/4"  (1915-18)

                 1919                               1920-24
1-2-digit  5 1/2" x  5 1/4"             1-3-figure  6" x  9"
  3-digit  5 1/2" x  7 3/4"               4-figure  6" x 11 3/4"
  4-digit  5 1/2" x 10 1/2"               5-figure  6" x 15"
  5-digit  5 1/2" x 13 3/8"               6-figure  6" x 17 3/4"

            1925-31
1-4-figure  6" x  9 1/2"              1932-56       6" x  9 1/4"
  5-figure  6" x 11 3/4"              1957-present  6" x 12"
  6-figure  6" x 15"

1937-56, 1959-60 TABS      1 1/16" x 1 5/8"
1957-58, 1962-63 TABS      1 3/8"  x 1 5/8"
1963-93          STICKERS  1 1/4"  x 1 3/8"
1998-2003        STICKERS  1 1/4"  x 1 1/2"