"unsupported operand type(s) for -: 'int' and 'str'" error

Using version 1.0.4 for this file I get:

➜ csvlook logs/BigBuckBunny-1080-2pass-maxrate1-bufsize1_quality.csv
unsupported operand type(s) for -: 'int' and 'str'

(.log extension used instead of .csv to upload here.)