How to put pivot table using Shell script

I have data in a CSV file as below...

Emailid  Storeid      

a@gmail.com 2000

b@gmail.com 2001

c@gmail.com 2000

d@gmail.com 2000

e@gmail.com 2001

I am expecting below output, basically finding out how many email ids are there for each store.

StoreID    Emailcount

2000           3

2001           2

So far i tried to solve my issue

IFS=","
while read f1 f2
do
awk -F, '{ A[$1]+=$2 } END { OFS=","; for (x in A) print x,A[x]; }' > /home/ec2-user/storewiseemials.csv
done < temp4.csv

With the above shell script i am not getting desired output, Can you guys please help me?

Solution

Using miller (https://github.com/johnkerl/miller) and starting from this (I have used a CSV, because I do not know if you use a tab or a white space as separator)

Emailid,Storeid
a@gmail.com,2000
b@gmail.com,2001
c@gmail.com,2000
d@gmail.com,2000
e@gmail.com,2001

and running

mlr --csv count-distinct -f Storeid -o Emailcount input >output

you will have

+---------+------------+
| Storeid | Emailcount |
+---------+------------+
| 2000    | 3          |
| 2001    | 2          |
+---------+------------+