Is that 1 in 1000 for all C++ written since 1985, or is it "like for like" and all C++ written since 2010 when Rust first appeared or later when Rust stabilised

Is that 1 in 1000 for all C++ written since 1985, or is it "like for like" and all C++ written since 2010 when Rust first appeared or later when Rust stabilised? Chrome was 2008. No idea if the code base has been completely "modernised" or not.