#166 correcting the offset in the description

GRIB2_Template_4_91_ProductDefinitionTemplate_en.csv

@@ -37,6 +37,6 @@ categorical forecasts at a horizontal level or in a horizontal layer in a contin
 categorical forecasts at a horizontal level or in a horizontal layer in a continuous or non-continuous time interval,(63+12(NC-1))-(66+12(NC-1)),"Length of the time range over which statistical processing is done, in units defined by the previous octet",,,,,Operational
 categorical forecasts at a horizontal level or in a horizontal layer in a continuous or non-continuous time interval,(67+12(NC-1)),Indicator of unit of time for the increment between the successive fields used,(see Code table 4.4),,4.4,,Operational
 categorical forecasts at a horizontal level or in a horizontal layer in a continuous or non-continuous time interval,(68+12(NC-1))-(71+12(NC-1)),"Time increment between successive fields, in units defined by the previous octet",(see Notes 3 and 4),"7,157",,,Operational
-categorical forecasts at a horizontal level or in a horizontal layer in a continuous or non-continuous time interval,,"72-nn   These octets are included only if n > 1, where nn = 72+12(n-1)+12(NC-1)",,,,,Operational
+categorical forecasts at a horizontal level or in a horizontal layer in a continuous or non-continuous time interval,,"72-nn   These octets are included only if n > 1, where nn = 71+12(n-1)+12(NC-1)",,,,,Operational
 categorical forecasts at a horizontal level or in a horizontal layer in a continuous or non-continuous time interval,(72+12(NC-1))-(83+12(NC-1)),"As octets (60+12(NC-1)) to (71+12(NC-1)), next innermost step of processing",,,,,Operational
 categorical forecasts at a horizontal level or in a horizontal layer in a continuous or non-continuous time interval,(84+12(NC-1))-nn,"Additional time range specifications, included in accordance with the value of n. Contents as octets (60+12(NC -1)) to (71+12(NC -1)), repeated as necessary",,,,,Operational