Real earnings rose by 3 percent over the last three years.
Earnings before interest and tax rose from £22m to £31m.
For the year, earnings rose 11 percent, to $870 million.
The Government also said that average earnings rose 7.75 percent in the first half of 1987.
In total, earnings rose about 71 percent, to $1.55 billion.
The earnings should rise to $2.15 a share in 1998, she said.
Earnings rose 47 percent compared with a year earlier to $2.22 billion, or $1.45 a share.
Earnings for the year rose 21.3 percent to $413 million, on sales of $4.12 billion.
Earnings per share rose to $3.51 for the year, from $1.97.
Earnings per share rose to $1.38, from $1.20 a year earlier.