We analyze how trade dependencies have evolved over time to better understand how they relate to vulnerabilities. We focus on the EU-27 and apply the bottom-up approach laid out by the European Commission (EC) using trade data from 1996 to 2019. The number of dependent products has shown no clear pattern since the mid-1990s, nor has their sectoral composition. The geography of dependencies has, however, evolved towards dependencies concentrated on Chinese suppliers, but this shift had already occurred in 2010. The products identified as dependent exhibit significant churning over time: one out of five dependent products in 2018 was not identified as such one year later in 2019 and close to half of dependent products in 2014 were not identified as such five years later.