|Code|Year|Code|Year|Code|Year|
|---|---|---|---|---|---|
|A|1927|A1|1955|A2|1981|
|B|1928|B1|1956|B2|1982|
|C|1929|C1|1957|C2|1983|
|CH|1930|CH1|RIEN|CH2|RIEN|
|D|1931|D1|1958|D2|1984|
|E|1932|E1|1959|E2|1985|
|F|1933|F1|1960|F2|1986|
|G|1934|G1|1961|G2|1987|
|H|1935|H1|1962|H2|1988|
|I|1936|I1|1963|I2|1989|
|J|1937|J1|1964|J2|1990|
|K|1938|K1|1965|K2|1991|
|L|1939|L1|1966|L2|1992|
|LL|1940|LL1|RIEN|LL2|RIEN|
|M|1941|M1|1967|M2|1993|
|N|1942|N1|1968|N2|1994|
|Ñ|1943|Ñ1|1969|Ñ2|1995|
|O|1944|O1|1970|O2|1996|
|P|1945|P1|1971|P2|1997|
|Q|1946|Q1|1972|Q2|1998|
|R|1947|R1|1973|R2|1999|
|S|1948|S1|1974|S2|2000|
|T|1949|T1|1975|T2|2001|
|U|1950|U1|1976|U2|2002|
|V|1951|V1|1977|V2|2003|
|X|1952|X1|1978|X2|2004|
|Y|1953|Y1|1979|Y2|2005|
|Z|1954|Z1|1980|Z2|2006|

Question: what was the only year to use the code ch?
Answer: 1930