It was quite bad.

2010 WRs:
132 cathces on 255 targets for 1,542 yards with 15 TDs and 7 INTs .518% and 116.48 passer rating.

By comparison the 2014 WRs have been much better:
150 cathes on 250 targets for 1,893 yards with 13 TDs 4 INTs .600% and 137.56 passer rating.

Other past years for WRs:
2013:
173 catches on 313 targets for 2,377 yards with 17 TDs 9 INTs .553% and 131.24 passer rating.

2012:
192 catches on 312 targets for 2,090 yards with 15 TDs 15 INTs .615% and 124.06 passer rating.

2011:
181 catches on 320 targets for 2,371 yards with 23 TDs 13 INTs .566% and 134.40 passer rating