How to compute percentages

I have a query that is like this:

SELECT cl1, count(cl2) as no_accounts, sum(cl2) as consumption
FROM tbl1
WHERE cl2 != 0
GROUP BY cl1
ORDER BY cl1;

this gives me the following output

cl1 no_accounts consumption
a 2 50
b 1 100
c 5 30

On the same query i want to calculate percentages no_accounts and
consumption without having to create a table or view and then computing the
percentages

cl1 no_accounts percent_no_accounts consumption
percent_no_consumption
a 2 25
50 27
b 1 12
100 55
c 5 62
30 16