I think the $0.00 countries were just skipped (or missing from source data). In Finland, using "the operator with the largest marketshare in the country, using

I think the $0.00 countries were just skipped (or missing from source data). In Finland, using "the operator with the largest marketshare in the country, using the least expensive plan with a (minimum) data allowance of 500 MB over (a minimum of) 30 days" yields a 9.90€/month plan (Saunalahti Tarkka 1M) which has unlimited data (like most plans here).