How do I write this on MySQL

Write a query to list the country ( from the customer table) and the number of orders placed by the customers in that country. Express this number as a percentage of total orders . order the results in descending orders of the percentage.

Customers customerNumber INT(11) CustomerName VARCHAR(50) contactLastName VARCHAR(50) contactFirstName VARCHAR(50) phone VARCHAR(50) addressLine1 VARCHAR(50) addressLine2 VARCHAR(50) Orders orderNumber INT(11) OrderDate DATETIME requiredDate DATETIME shippedDate DATETIME status VARCHAR(15) comments TEXT city VARCHAR(50) state VARCHAR(50) 1 postalCode VARCHAR(15) country VARCHAR(50) osales RepEmployeeNumber lNT(11) creditLimit DOUBLE customerLocation POINT Indexes customerNumber INT(11) ndexes Offices officeCode VARCHAR(10) city VARCHAR(50) phone VARCHAR(50)