Write SQL query to solve given problem: What is the difference in the most populated city of Allentown-Bethlehem-Easton, PA-NJ in 2020 against its population in 2010?. Keep the solution inside sql tag ```sql [SQL-Query] ```
SELECT T1.population_2020 - T1.population_2010 AS result_data FROM zip_data AS T1 INNER JOIN CBSA AS T2 ON T1.CBSA = T2.CBSA WHERE T2.CBSA_name = 'Allentown-Bethlehem-Easton, PA-NJ' ORDER BY T1.population_2020 DESC LIMIT 1