Actually, you did it at every step
To get from those 5.2%(Pentax share for DSLRs) 0.83%, you multiplied the 5.2% with 15.9% - DSLRs share in total cameras (compacts included). But the DSLR share in ILCs is 59.9%.
Pentax actually has 3.1% (DSLRs) + 3.9% (MILCs) of the ILCs. As value, it's 3.7% (DSLRs) + 2.9% (MILCs) of the ILCs.
There was nothing wrong with how you did it, of course; I just thought the inclusion of the compacts had to be clarified.
Thank you for taking the time to make this table.