Roth Conversion to Already Existing Roth Account

Does the 5 year rule apply to all funds in a Roth account?   I already have a Roth account with say $100k.   This year I want to roll another $100k from a regular IRA to my Roth account.   Does the 5 year rule affect the entire $$200K now in the account, or just the $100k that was rolled over this year?