First issue 1956?
used passenger plate colors through 1975
Special Mobile (Equipment) plates used primarily on wreckers and mobile cranes.
1/2 year issues known at least 1962-1985
1956 (pair) "SME" prefix
black/yellow
1957 (pair) "SME" prefix
white/blue
1958 (pair) "SME" prefix
blue/white
1959 (pair) "SME" prefix
white/blue
1960 (pair) "SME" prefix
blue/white
1961 (pair) "SME" prefix
red/white
1962 (pair) "SME" prefix
1/2 year marked "SC - APRIL 30TH - 62" bottom
white/red
1963 (pair) "SME" prefix
1/2 year marked "SC - APRIL 30TH - 63" top
white/green
1964 (pair) "SME" prefix
white/black
1965 (pair) "SME" prefix
1/2 year marked "SC - APRIL 30TH - 65" top
black/white
1966 (pair) "SM" prefix
white/blue
1967 (pair) "SM" prefix
blue/white
1968 (pair) "SM" prefix
white/black
1969 (pair) "SM" prefix
white/blue
1970 (pair) "SM" prefix
white/green
1971 (pair) "SM" prefix
white/brown
1972 (pair) "SM" prefix
1/2 year marked MAY 15TH
white/black
1973 (pair) "SM" prefix
1/2 year marked MAY 15TH
white/blue
1974 (pair) "SM" prefix
1/2 year marked MAY 15TH
white/green
1975 (single) "SM" prefix
1/2 year marked MAY 15TH
white/maroon
1976 (single) "SM" prefix
blue/white
1977 (single) "SM" prefix
red/white
1978 (single) "SM" prefix
green/white
1979 (single) "SM" prefix
black/white
1980 (single) "SM" prefix
blue/white
1981 (single) "SM" prefix
red/white
1982 (single) "SM" prefix; "EXP DEC. 31ST 82" top
green/white
1983 (single) "SM" prefix; "EXP DEC. 31ST 83" bottom
black/white
1984 (single) "SM" prefix; "EXP DEC. 31 84" top
blue/white
1985 (single) "SM" prefix; "EXP DEC. 31 85" bottom
red/white
1986 (single) "SM" prefix; "EXP 12/31" bottom corners
green/white
1987 (single) "SM" prefix; "EXP 12/31" bottom corners
black/white
1988 (single) "SM" prefix; "EXP SPECIAL MOBILE 12/31" bottom
blue/white
1989-1990 (single) "SM" prefix; stickered, blue "89" sticker, 90 passenger sticker
numbering began at SM10001; early: embossed border, later: no border
red/white
1991-2015 (single) "SM" prefix; stickered
"91" non-pass sticker, 92-present passenger stickers
black embossed border (early with no border) numbering began at SM10001
black/white
2016-present (single) "S/M" stacked prefix; non-passenger 'standard design', palmetto tree left
numbering continued from previous design
black/white