"BFXB" 1991 ZR1 stock bin.

The Target RPMs table has:

Deg C RPM
-40 05
-28 03
-16 03
-4 59
8 1B
20 08
32 02
44 00
56 38
68 68
80 60
.. ..
152 60

What do those hex values in the RPM column indicate - IAC counts, tach speed?