How many bilateral relationships share a common currency per year in the sample?

52,670 observations per year

ta year comcur
        
      year  |         0          1        |     Total
-----------+----------------------+----------
      1948 |    50,996      1,674 |    52,670
      1949 |    51,046      1,624 |    52,670
      1950 |    51,046      1,624 |    52,670
      1951 |    51,070      1,600 |    52,670
      1952 |    51,070      1,600 |    52,670
      1953 |    51,070      1,600 |    52,670
      1954 |    51,126      1,544 |    52,670
      1955 |    51,126      1,544 |    52,670
      1956 |    51,126      1,544 |    52,670
      1957 |    51,126      1,544 |    52,670
      1958 |    51,142      1,528 |    52,670
      1959 |    51,156      1,514 |    52,670
      1960 |    51,156      1,514 |    52,670
      1961 |    51,188      1,482 |    52,670
      1962 |    51,254      1,416 |    52,670
      1963 |    51,222      1,448 |    52,670
      1964 |    51,230      1,440 |    52,670
      1965 |    51,336      1,334 |    52,670
      1966 |    51,452      1,218 |    52,670
      1967 |    51,916        754 |    52,670
      1968 |    51,916        754 |    52,670
      1969 |    51,986        684 |    52,670
      1970 |    51,976        694 |    52,670
      1971 |    52,086        584 |    52,670
      1972 |    52,114        556 |    52,670
      1973 |    52,114        556 |    52,670
      1974 |    52,148        522 |    52,670
      1975 |    52,164        506 |    52,670
      1976 |    52,208        462 |    52,670
      1977 |    52,246        424 |    52,670
      1978 |    52,252        418 |    52,670
      1979 |    52,270        400 |    52,670
      1980 |    52,270        400 |    52,670
      1981 |    52,268        402 |    52,670
      1982 |    52,292        378 |    52,670
      1983 |    52,292        378 |    52,670
      1984 |    52,268        402 |    52,670
      1985 |    52,258        412 |    52,670
      1986 |    52,272        398 |    52,670
      1987 |    52,272        398 |    52,670
      1988 |    52,272        398 |    52,670
      1989 |    52,272        398 |    52,670
      1990 |    52,272        398 |    52,670
      1991 |    52,280        390 |    52,670
      1992 |    52,280        390 |    52,670
      1993 |    52,280        390 |    52,670
      1994 |    52,310        360 |    52,670
      1995 |    52,310        360 |    52,670
      1996 |    52,310        360 |    52,670
      1997 |    52,284        386 |    52,670
      1998 |    52,284        386 |    52,670
      1999 |    51,968        702 |    52,670
      2000 |    51,968        702 |    52,670
      2001 |    51,928        742 |    52,670
      2002 |    51,886        784 |    52,670
      2003 |    51,886        784 |    52,670
      2004 |    51,886        784 |    52,670
      2005 |    51,886        784 |    52,670
      2006 |    51,886        784 |    52,670
      2007 |    51,842        828 |    52,670
      2008 |    51,748        922 |    52,670
      2009 |    51,698        972 |    52,670
      2010 |    51,698        972 |    52,670
      2011 |    51,646      1,024 |    52,670
      2012 |    51,646      1,024 |    52,670
      2013 |    51,646      1,024 |    52,670
      2014 |    51,592      1,078 |    52,670
      2015 |    51,536      1,134 |    52,670
-----------+----------------------+----------
     Total | 3,523,026     58,534 | 3,581,560


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