What file **slope51.dat** means:
the 1st row gives the slope of the linear fit of the dataset relative to
November 2011, fitted from Jan 1951 to Nov 2011;
the 2nd row gives the slope of the linear fit of the dataset relative to
December 2011, fitted from Jan 1951 to Dec 2011;
.
.
.
the 10th row gives the slope of the linear fit of the dataset relative to
August 2012, fitted from Jan 1951 to Aug 2012;
.
.
the 20th row gives the slope of the linear fit of the dataset relative to
Jun 2013, fitted from Jan 1951 to Jun 2013;
the 21st row gives the slope of the linear fit of the dataset relative to
Jul 2013, fitted from Jan 1951 to Jul 2013;
.
.
the last row gives the slope of the linear fit of the dataset relative to
Mar 2016, fitted from Jan 1951 to Mar 2016;
So, the fit uses an increasing number of data points: to compare with the
Karl et al.,2015 fit (1951-2012) the actual row to be read is the 14th's
(of the data, the 16th of the file), marked by a double asterisk (**) and
corresponding to 12/12.