average total/NR

awk '	# Invoke awk and start the script specifying actions to be performed.
function print_total() {
	# Define function to print the total and average acccumulated for the
	# previous set of lines with the same four characters at the start of
	# the 1st field.
	printf("\n    Total Sum of %s: %d\n", last, total)
	printf("\nTotal Average of %s: %.2f\n", last, total / count)
}
last != substr($1, 1, 4) {
	# Perform the actions in this group when the 1st four characters in the
	# 1st field on this line is not the same as the 1st four characters in
	# the 1st field that we saw on the previous line.  Since there is no
	# previous line when we are reading the 1st line from our input file,
	# we also perform the actions in this group when processing the 1st
	# line in the input file.
	if(NR > 1) {
		# Perform these actions when we are not processing line #1.
		print_total()				# Print the total for
							# for the previous set.
		printf("\n=======================\n")	# Print a set separator.
	}
	# Save the 1st four characters from this line to compare against
	# subsequent input lines.
	last = substr($1, 1, 4)
	# Clear the count and total for this new set.
	count = total = 0
}
{	# Perform the actions in this group for every line in the input file.
	print		# Print the current input line.
	count++		# Increment the number of lines seen in this set.
	total += $2	# Add the contents of the 2nd field on this line to the
			# total for this set.
}
END {	# Perform the actions in this group after we have read the last line of
	# input from the input file.
	print_total()	# Print the total and average for the last set.
}' hhhh	# End the awk script and name the file to be processed.