If you look at the full list (available e.g. here https://www.newsweek.com/trump-reciprocal-tariff-chart-20545...), some countries (most prominently Russia) are not on it. Whether that means anything is debatable, but Mexico and Canada, who were explicitly "spared" from these tariffs (but have other tariffs "tailor-made" especially for them), are also not on the list.
Even the UK gets 10% which is truly mad given we have balanced trade and tarrifs (if anything the US tariffed the UK more than they did them).
^So essentially MAX(10%,(imports-exports)/imports)