This is recent data released by NASA's Orbital Debris Office. As a result of over 4 700 launches since 1957, there are currently around 19 000 pieces of trackable debris. Most of this derives from missions launched by the USA, the former USSR and China.
The missions which produced the greatest quantity of debris are:
Name Year Debris Cause of Breakup
Fengyun-1C 2007 2,841 Intentional Collision
Cosmos 2251 2009 1,267 Accidental Collision
STEP 2 Rocket Body 1996 713 Accidental Explosion
Iridium 33 2009 521 Accidental Collision
Cosmos 2421 2008 509 Unknown
SPOT 1 Rocket Body 1986 492 Accidental Explosion
OV2-1/LCS 2 Rocket 1965 473 Accidental Explosion
Nimbus 4 Rocket Body 1970 374 Accidental Explosion
TES Rocket Body 2001 370 Accidental Explosion
CBERS 1 Rocket Body 2000 343 Accidental Explosion
What's interesting to note about this is that the most frequent source of debris in the top ten is rocket bodies, and I presume this is largely due to residual fuel (there is a large amount of literature on the problem of passivation at the end of mission life). And six are also within the last ten years, suggesting that, despite guidelines for limiting the creation of orbital debris being around for a decade or more, they may not be very effective ...... Note also that there are only two accidental collisions in this list, which supports my argument that the risks posed by large objects that may have heritage value, if they are left in orbit, are not as great as we might think.
Of course this is only the top ten, and a more thorough investigation of the figures may be illuminating.