--- coverage of epoch_param ---
 first_epoch | last_epoch | rows_present | epochs_spanned 
-------------+------------+--------------+----------------
         208 |        652 |          445 |            445
(1 row)


--- minPoolCost change points ---
 effective_from_epoch | previous_ada |  new_ada   |   epoch_start_utc   |              kind              
----------------------+--------------+------------+---------------------+--------------------------------
                  208 |              | 340.000000 | 2020-07-29 21:44:51 | initial value (Shelley launch)
                  445 |   340.000000 | 170.000000 | 2023-10-27 21:45:10 | change
(2 rows)


--- how long has the current value been in force ---
 unchanged_since_epoch |      since_utc      | tip_epoch | epochs_unchanged | approx_years 
-----------------------+---------------------+-----------+------------------+--------------
                   445 | 2023-10-27 21:45:10 |       652 |              207 |         2.83
(1 row)