@Vjback
.. that of Zcash (where your transaction is hidden amongst all outstanding transactions)
Not just all outstanding (JoinSplit) transactions: in Zcash, your notes are hidden amongst all other notes that have ever been created. Combined with the fact that coinbase must be entirely spent to a z-address using a JoinSplit, this means that the set of possible JoinSplit outputs that your JoinSplit could be using as an input increases continuously.
Note that this assumes no other information leakage. See e.g. https://github.com/zcash/zcash/issues/778 and https://github.com/zcash/zcash/issues/1360 for work being done to eliminate potential sources of incidental information leakage.