query 1.select operator_id,
sum(blocked) as blocked,
count(distinct(customer_id)) as customer from fact_roaming where blocked =1 and entry_type_id=2 
group by operator_id order by 2 desc limit 4

query 2.select operator_id,
sum(blocked) as blocked,
count(distinct(customer_id)) as customer from fact_roaming where blocked =1 and entry_type_id=1 
group by operator_id order by 2 desc limit 4;

how can i union these two queries using union