Below is the list of tables from the database along with their columns and datatype. Need to generate an accurate SQL query for the question.
Only use the columns present in the respective table. Only use the columns which are required to generate the SQL query. Only use table joins if required and not otherwise.

### Tables ###
TABLE: CREATE TABLE market ( Market_ID int, District text, Num_of_employees int, Num_of_shops real, Ranking int )
TABLE: CREATE TABLE phone ( Name text, Phone_ID int, Memory_in_G int, Carrier text, Price real )
TABLE: CREATE TABLE phone_market ( Market_ID int, Phone_ID text, Num_of_stock int )

### Question ###
Create a pie chart showing the number of carrier across carrier.

### Accurate SQL ###

SELECT Carrier, COUNT(Carrier) FROM phone GROUP BY Carrier