excess        recession  recession  length
Year  500ew  BCC0  return  ....    start       end     months
1962   -12    -4     8           Apr-1960   Feb-1961     10
 
1969   -18   -10     8           Dec-1969   Nov-1970     11
1970    5     20     15
 
1974   -23    12     35          Nov-1973   Mar-1975     16
 
1981    5      9     5           Jul-1981   Nov-1982     16
1982    30    39     9
 
2001    0      6     6           Mar-2001   Nov-2001     8
2002   -18     3     20
 
2008   -39    -8     32          Dec-2007   Jun-2009     18
2009    46    52     5
 
                                 Aug-1957   Apr-1958     8
                                 Jan-1980   Jul-1980     6
                                 Jul-1990   Mar-1991     8
                                 Feb-2020   Apr-2020     2