So what do these numbers mean, well since we want to look at the relationship from a holistic standpoint the only really important number in this context is "weighted mean tariff". But these numbers raw give you a skewed picture of the US-China trade relationship seeing as they are not sole trading partners (they trade with other countries too) and that needs to be corrected for when analyzing the data.

Since around 35% of all us trade is totally free (Canada, Mexico etc) the 1.4% number is very skewed if we are to isolate it in relation to China, another issue is the trade with the EU which also lies very low and lowers the US's weighted mean tariff. Corrected for the free trade alone we get a weighted mean tariff closer to 2.1 rather than 1.4 when the US trades with non free trade agreement partners.

China on the other hand has it the reversed because the tariffs it has on other countries it trades with (SK, Japan, Brazil Russia) are higher than the tariffs it has with the US, and seeing as China only exports around 16.9% of its exports to the US we have a comparatively lower corrected estimate of 2.55 as the weighted mean tariff. This is after correcting for only three countries so it is due to fall after doing more but I've made my point.

All in all trade between the US and China in terms of tariffs is extremely fair on a macro scale (steel/solar subsidies and retaliatory tariffs notwithstanding).