Our friends at Opta have looked into this for you, Mats, and I can tell you that Manchester United have scored four goals from corners this season - all in home games. There is Michael Carrick against Everton, Nemanja Vidic against Wolves plus goals from Wayne Rooney against Hull City and Portsmouth. When you consider that United have received 274 corners this season (more than anybody else ahead of the midweek fixtures), that is not a high return. Only 1.46% of their corners result in goals.
However, that is not the worst conversion rate in the Premier League. Fulham have only scored twice from their 156 corners this season, while Burnley are yet to score a single goal from a corner - despite having received 160 of them this season.
At the other end of the scale, Manchester City have the best corner conversion rate, having scored 15 goals from 207 corners this season. That means that 7.25% of their corners result in goals.
Premier League corner conversion rates:
Team Corners taken Goals from corners % of corners resulting in a goal
Manchester City 207 15 7.25
Aston Villa 196 11 5.61
Blackburn Rovers 164 9 5.49
Stoke City 169 8 4.73
Sunderland 161 7 4.35
Portsmouth 166 7 4.22
Liverpool 240 10 4.17
West Ham United 168 7 4.17
Hull City 133 5 3.76
Everton 193 7 3.63
Tottenham Hotspur 198 7 3.54
Arsenal 231 7 3.03
Chelsea 269 7 2.6
Birmingham 163 4 2.45
Bolton 169 4 2.37
Wigan 150 3 2
Wolves 181 3 1.66
Manchester United 274 4 1.46
Fulham 156 2 1.28
Burnley 160 0 0