2024 18 USC 503 – Postmarking stamps

2023 18 USC 503 – Postmarking stamps

2022 18 USC 503 – Postmarking stamps

2021 18 USC 503 – Postmarking stamps

2020 18 USC 503 – Postmarking stamps

2018 18 USC 503 – Postmarking stamps

2017 18 USC 503 – Postmarking stamps

2015 18 USC 503 – Postmarking stamps

2014 18 USC 503 – Postmarking stamps

2013 18 USC 503 – Postmarking stamps

2012 18 USC 503 – Postmarking stamps

2010 18 USC 503 – Postmarking stamps