#NEWLINE# @ staticmethod #NEWLINE# def average_age( changes , ages ) : #NEWLINE# #INDENT# if ( len ( changes ) == 0 ) : #NEWLINE# #INDENT# return 0 #NEWLINE# #UNINDENT# total = 0 #NEWLINE# for change in total : #NEWLINE# #INDENT# total += ages [ change ] #NEWLINE# #UNINDENT# return format_delta ( ( total / len ( changes ) ) )