Out of the 19 OTICs listed, only 4 have issued any certificates so far. Only 12 certificates have been issued between 2022-06-30 and 2024-03-31. There seem to be 8 North American OTICs.

A list of OTICs including (what I presume is) their opening dates can be found here.

Here's a summary of OTICs, their opening dates and the number of issued certificates.

Date          Certificates   OTIC
2023-07-04    0              "North American OTIC in Central Iowa (ARA)"
2023-07-04    0              "North American OTIC in Washington DC/Arlington VA (Virginia Tech)"
2023-07-04    0              "North American OTIC in Salt Lake City (POWDER)"
2023-07-04    0              "North American OTIC at MITRE"
2023-07-04    0              "North American OTIC in the Boston Area (UNH-IOL)"
2023-07-04    0              "North American OTIC in the Raleigh-Durham Research Triangle Park Area (AERPAW)"
2023-06-01    0              "North American OTIC in the Boston Area (Northeastern University)"
2023-03-06    0              "Asia & Pacific OTIC by ritt7layers"
2023-03-06    0              "Asia & Pacific OTIC in Singapore"
2023-01-17    0              "North American OTIC in NYC Metro Area/East (COSMOS)"
2022-12-20    1              "Japan OTIC"
2022-12-20    1              "Korea OTIC"
2021-08-11    0              "European OTIC in Madrid"
-             0              "European OTIC in Torino"
-             0              "European OTIC in Berlin"
-             0              "European OTIC in Paris"
-             7              "Auray OTIC and Security lab"
-             3              "Asia & Pacific OTIC in PRC"
-             0              "Kyrio O-RAN Test and Integration Lab"