A social media company manages a multi-AZ VPC environment consisting of public subnets and private subnets. Each public subnet contains a NAT Gateway as well as an Internet Gateway. Most of the company's applications are deployed in the private subnets and these applications read and write data to Kinesis Data Streams. The company has hired you as an AWS Certified Solutions Architect Professional to reduce costs and optimize the applications. Upon analysis in the AWS Cost Explorer, you notice that the cost in the EC2-Other category is consistently high due to the increasing NAT Gateway data transfer charges. What do you recommend to address this requirement?