how many different codes were used from 1953 to 1958?
6
col : code | year | code | year | code | year row 1 : a | 1927 | a1 | 1955 | a2 | 1981 row 2 : b | 1928 | b1 | 1956 | b2 | 1982 row 3 : c | 1929 | c1 | 1957 | c2 | 1983 row 4 : ch | 1930 | ch1 | rien | ch2 | rien row 5 : d | 1931 | d1 | 1958 | d2 | 1984 row 6 : e | 1932 | e1 | 1959 | e2 | 1985 row 7 : f | 1933 | f1 | 1960 | f2 | 1986 row 8 : g | 1934 | g1 | 1961 | g2 | 1987 row 9 : h | 1935 | h1 | 1962 | h2 | 1988 row 10 : i | 1936 | i1 | 1963 | i2 | 1989 row 11 : j | 1937 | j1 | 1964 | j2 | 1990 row 12 : k | 1938 | k1 | 1965 | k2 | 1991 row 13 : l | 1939 | l1 | 1966 | l2 | 1992 row 14 : ll | 1940 | ll1 | rien | ll2 | rien row 15 : m | 1941 | m1 | 1967 | m2 | 1993 row 16 : n | 1942 | n1 | 1968 | n2 | 1994 row 17 : ñ | 1943 | ñ1 | 1969 | ñ2 | 1995 row 18 : o | 1944 | o1 | 1970 | o2 | 1996 row 19 : p | 1945 | p1 | 1971 | p2 | 1997 row 20 : q | 1946 | q1 | 1972 | q2 | 1998 row 21 : r | 1947 | r1 | 1973 | r2 | 1999 row 22 : s | 1948 | s1 | 1974 | s2 | 2000 row 23 : t | 1949 | t1 | 1975 | t2 | 2001 row 24 : u | 1950 | u1 | 1976 | u2 | 2002 row 25 : v | 1951 | v1 | 1977 | v2 | 2003 row 26 : x | 1952 | x1 | 1978 | x2 | 2004 row 27 : y | 1953 | y1 | 1979 | y2 | 2005 row 28 : z | 1954 | z1 | 1980 | z2 | 2006
how many different codes were used from 1953 to 1958?
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
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