You can search the masternode network using the PROTX hash of the masternode or the collateral outpoint, you will then see a history of that masternode displayed over time, the data is coming from the Dash Stats page. A protx hash should look similar to this.
dffdcfbdf94d4b30fd78e1f0a2521300c1cbfef8bc2de9ab080595ca9ca175b1
It is not case sensitive and a collateral outpoint should look similar to this.
f3454de61bcf7cd61aada372f94d4c804d5f90bf085d146661f5a56edaffd32a-0
Which is also not case sensitive, however, the dash ‐ must be used to separate the hash and the index.