Based on the provided process variants and their execution times for both the protected and unprotected groups, here are the main differences:

1. Frequency of Loan Denial: The most frequent process variant for the protected group ends with the application being rejected (frequency = 960), while the most frequent process variant for the unprotected group results in loan denial (frequency = 2709). This suggests that the protected group may be more likely to have their applications rejected earlier in the process compared to the unprotected group.
2. Frequency of Loan Approval: The unprotected group has a higher frequency of loan approval compared to the protected group. This is evident from the number of process variants that result in signing a loan agreement, which is higher for the unprotected group (frequency = 1656) than the protected group (frequency = 31). This indicates a potential discrepancy in the loan approval rates between the two groups.
3. "Skipped Examination" activity: The unprotected group has a process variant that includes a "skipped examination" activity, which is not present in any of the process variants for the protected group. This suggests that the unprotected group may be subject to different evaluation criteria or may receive preferential treatment, allowing them to skip certain steps in the process.
4. Application Rejection: The protected group has a significantly higher frequency of application rejection (frequency = 960) compared to the unprotected group (frequency = 664). This indicates that the protected group may be more likely to have their applications rejected at an earlier stage of the process.
5. Execution Time: The average execution time for the most frequent process variant for the protected group (219999.156) is lower than that of the unprotected group (340005.309). However, the protected group has several process variants with very long execution times, such as those involving multiple visits to assess collateral. This suggests that the protected group may experience longer and more complex loan application processes compared to the unprotected group.
6. Co-signer Requirements: Both groups have process variants that involve requesting a co-signer on the loan, but the frequency of these variants is higher for the protected group. Additionally, the protected group has variants that involve requesting a co-signer and making multiple visits to assess collateral, which are not present in the unprotected group's variants. This suggests that the protected group may face stricter requirements for securing a co-signer and may undergo more rigorous evaluations of their collateral.

In summary, the main differences between the treatment of the protected and unprotected groups include discrepancies in loan approval rates, the presence of a "skipped examination" activity for the unprotected group, higher frequencies of application rejection and co-signer requirements for the protected group, and longer execution times for certain process variants in the protected group. These differences may indicate potential unfair treatment or biases in the loan application process.