The following are the income statements of Amazon.com, Inc. for the years ended December 31, 2022, and 2021.

Amazon.com, Inc.	2022	2021
Sales	$469,822	$386,064
Cost of Goods Sold	$281,795	$233,307
Gross Profit	$188,027	$152,757
Operating Expenses	$110,824	$88,234
Net Income	$33,364	$21,331

Requirements:

1. Calculate the gross profit margin for each year.
2. Calculate the operating profit margin for each year.
3. Compute the net profit margin for each year.
4. Analyze the changes in Amazon's profitability from 2021 to 2022.