UK Census 2011: Longevity and our 'missing' 90 year olds

The 2011 census for the United Kingdom has revealed many interesting statistics.  One such out of kilter statistics has been highlighted by Richard Willets in an article titled “Longevity and our 'missing' 90-year-olds” in “The Actuary” published on 28 Nov 2012. Richard highlights that there are now fewer elderly people in England & Wales than was previously estimated. The census data showed that there were 30,000 fewer people aged in their 90s than previously expected.  This represents a reduction of around 15% from the estimated value prior to the data revealed from the 2011 census. 

Two immediate corollaries are discussed in the article. One that the mortality rates for the population of England & Wales at ages above 90 will be higher than previously thought. This means that life expectancy at age 65 should be slightly lower. Second, that the recent pace of improvement, in high age mortality rates, will have been over-stated.