VCF0875a R Opinion: Mention 2- Most Important National Problem

QUESTION:
---------
Most important national problem (2)

VALID_CODES:
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Codes 1-990 and:

MISSING_CODES:
--------------
991. 1968: No problem mentioned; no second or third
     problem; 1970: No problem mentioned; no second,
     third or fourth problem
996. No mentions, DK (1960,1964)
997. No problem mentioned, DK (1966); no second or third
     problem
998. DK (1968,1970,1972)
999. NA (1960,1964,1966,1968,1970,1972)
000. no Post IW; Form I,III,IV (1972)
Inap. question not used

NOTES:
------
See question wording and notes for 1974-later in VCF0875.
See Appendix note "MOST IMPORTANT PROBLEM 1960-1972".
GENERAL NOTE:
The is is the full 3-digit coding for the summary variable in
years 1960-1972.

WEIGHT:
-------
VCF0009/VCF0009a

TYPE:
-----
Numeric  Dec 0

SOURCE_VARS:
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1960:  600050B
1964:  640036
1966:  660019 
1968:  680048
1970:  700039(type 0)  
1972:  720546,720548