[OS] Average Electricity Usage

#!/bin/bash
if [ $# -ne 1 ]
then
    echo "USAGE: `basename $0` mesec"
    exit 1
fi
MONTH=$1
total_electricity=`cat electricity.txt | grep "|$MONTH|" | awk -F\| 'BEGIN {total=0} {total+=$5} END {print total}'`
number_people=`cat electricity.txt | grep "|$MONTH|" | wc -l`
if [ $number_people -eq 0 ]
then
    echo "Nema podatoci za toj mesec"
    exit $1
fi
average_electricity=`expr $total_electricity / $number_people`
touch people.txt
#just testing if I can put a shell variable into an awk command.
#it looks good on paper, but unfortunately all I have is a laptop
echo "`cat electricity.txt | grep "|$MONTH|" | awk -var $average_electricity '$3>$var {print $1 $2}'`" >> people.txt
cat people.txt