DIMENSIONS      1913             1914-15             1916-17
2-digit     5" x  7 1/4"     (As 3-d. 1914)      (As 3-d. 1917)
3-digit     5" x  8 3/8"      5" x  8 3/8"      5 3/8" x  9 1/2"
4-digit     5" x 10 5/8"      5" x 10 3/8"      5 3/8" x 11 1/4"
5-digit     5" x 12"          5" x 12"          5 3/8" x 13 1/8"

                1918              1919                1920
3-digit   5 3/8" x  8 7/8"   5 1/2" x 10 1/4"   5 1/2" x  8 5/8"
4-digit   5 3/8" x 10 7/8"   5 1/2" x 12 1/2"   5 1/2" x 11 1/2"
5-digit   5 3/8" x 12 7/8"   5 1/2" x 14 1/4"   5 1/2" x 13 1/2"
6-digit   5 3/8" x 15"       5 1/2" x 16"       5 1/2" x 15 3/8"

1919-20 TABS  3 3/4" x 3"  (Insert 5/8" x 1 5/8")

1921     1-5-digit  5"     x 10 1/4"
           6-digit  5"     x 12"

1922     1-3-digit  5 1/2" x 10 1/4"
           4-digit  5 1/2" x 12"
           5-digit  5 1/2" x 14 3/4"
           6-digit  5 1/2" x 16"

1923-29  1-4-digit  6"     x 10"
           5-digit  6"     x 12"
           6-digit  6"     x 14"

1930  All plates    5 1/2" x 12"

           1931-34, 1950-54         1935-49
2-6-digit  5 1/2" x 12 1/2"      5 1/4" x 12 1/2"
  7-digit  5 1/2" x 14 7/8"      5 1/4" x 14 7/8"

1955-present  All plates  6" x 12" (Standard bolt spread 1957-present)

1944-52          TABS      1 1/4" x 3"
1961             STICKER   1 1/2" x 1"
1976, 1998-2006  STICKERS  1"     x 1 1/2"
1978-97          STICKERS  1 1/4" x 1 3/4"