Versions:
python: 3.6.9
xlread: 1.2.0
openpyxl: 3.0.1

openpyxl, read-only
    Workbook loaded 1.14s
    OptimizationData 23.17s
    Output Model 0.00s
    >>DATA>> 0.00s
    Store days 0% 23.92s
    Store days 100% 17.35s
    Total time 65.59s
    0 cells in total

Versions:
python: 3.7.5
xlread: 1.2.0
openpyxl: 3.0.1

openpyxl, read-only
    Workbook loaded 0.98s
    OptimizationData 21.35s
    Output Model 0.00s
    >>DATA>> 0.00s
    Store days 0% 20.70s
    Store days 100% 16.16s
    Total time 59.19s
    0 cells in total

Versions:
python: 3.8.0
xlread: 1.2.0
openpyxl: 3.0.1

openpyxl, read-only
    Workbook loaded 0.90s
    OptimizationData 19.58s
    Output Model 0.00s
    >>DATA>> 0.00s
    Store days 0% 19.35s
    Store days 100% 15.02s
    Total time 54.85s
    0 cells in total