Postgres Sql7.3 Update

Dear Support Team,

I am currently using postgresql version 7.3 and I want to upgrade this
version.

So, can you please help me regarding the

1. List of upgrades/patches/service packs available to update the
postgresql 7.3 version

2. The list of feature that's updating in each new version of the
software.

Thanks & regards,
Kunwar Pal Singh Rawat

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