Table 7.

LS tracing rates

Census	Total enumerated	Total traced by NHS Digitala	Percent traced by NHS Digital	Forward linkage rates (%)
1971	529 900	523 800	98.8	91.3
1981	536 100	532 600	99.3	90.1
1991	543 900	537 200	98.8	88.0
2001	540 100	537 600	99.6	87.7
2011	585 800	580 600	99.1	N/A

Source: ONS LS.

^aThe same business area located in Southport, Lancashire has always carried out the tracing activity that supports the linkage of LS data. Between 1974 and 2008, this business area was part of OPCS/ONS. When the Statistics & Registration Service Act 2007 was enacted in 2008, this business area moved to the National Information Centre for Health & Social Care (NHSIC). NHSIC became NHS Digital on 1 August 2016.