The available information is given in the tables.
It should be noted that non-sanction detections that contribute to the percentage change in total detection rates have fallen in recent years reflecting a significant shift by many police forces away from recording detections of crime where no further action is taken. For this reason overall detection rates over time are not fully comparable. From 1 April 2007 the rules governing recording of non-sanction detections were revised to reduce the scope within which they can be claimed to a very limited set of circumstance. There are other changes affecting trends in detection rates that are discussed in section 3.5 of Volume two of Crime in England and Wales 2008-09, a copy of which has been deposited in the Library of the House.
Detection rates are a ratio of crime detected in a period to crimes recorded in a period. They are not based on tracking whether individual crimes recorded in a period have eventually been detected.
2000-01 2001-02 Police force area Rape Sexual assault Rape Sexual assault Avon and Somerset 43 48 27 32 Bedfordshire 33 54 25 42 British Transport Police n/a n/a n/a Cambridgeshire 50 59 46 51 Cheshire 85 84 81 76 Cleveland 59 68 65 69 Cumbria 70 85 74 69 Derbyshire 38 50 39 59 Devon and Cornwall 77 81 49 59 Dorset 36 52 39 48 Durham n/a n/a n/a n/a Dyfed-Powys 108 92 76 94 Essex 50 55 33 51 Gloucestershire 88 62 57 61 Greater Manchester 58 59 55 54 Gwent 98 90 93 89 Hampshire n/a n/a 53 56 Hertfordshire 66 65 62 75 Humberside 36 39 33 37 Kent 57 55 56 56 Lancashire 54 59 47 47 Leicestershire n/a n/a n/a n/a Lincolnshire 67 70 50 66 London, City of 50 29 22 68 Merseyside 74 66 53 54 Metropolitan Police 24 28 27 26 Norfolk 35 48 36 48 Northamptonshire 71 80 64 62 Northumbria 48 54 43 49 North Wales 64 74 35 56 North Yorkshire 75 73 59 64 Nottinghamshire 50 41 36 42 South Wales 88 71 90 75 South Yorkshire n/a n/a 72 60 Staffordshire 38 39 35 33 Suffolk 35 57 30 51 Surrey 28 41 42 40 Sussex 34 47 35 48 Thames Valley 26 48 32 42 Warwickshire 52 46 30 57 West Mercia 57 55 44 50 West Midlands 54 51 45 51 West Yorkshire n/a n/a 55 62 Wiltshire 32 36 46 47 England and Wales2,3 42 47 41 45 n/a = Not available. 1 The data in this table is prior to the introduction of the National Crime Recording Standard in April 2002. These figures are not direct comparable with those for later years. 2 For 2000-01 excludes British Transport Police, Durham, Hampshire, Leicestershire, South Yorkshire and West Yorkshire. 3 For 2001-02 excludes British Transport Police. Durham and Leicestershire. Note: Offences detected in any given year may have been initially recorded in a previous year and for this reason some percentages may exceed 100.
2002-03 2003-04 2004-05 2005-06 2006-07 2007-08 2008-09 Police force area Rape Sexual assault Rape Sexual assault Rape Sexual assault Rape Sexual assault Rape Sexual assault Rape Sexual assault Rape Sexual assault Avon and Somerset 22 26 21 26 18 19 22 24 20 22 25 23 21 23 Bedfordshire 29 35 21 25 23 38 23 25 15 37 18 20 16 26 British Transport Police 73 27 50 26 21 22 45 29 37 27 18 30 23 29 Cambridgeshire 29 32 15 30 21 30 22 30 15 30 19 23 23 33 Cheshire 48 55 29 47 28 43 28 39 30 36 31 37 26 38 Cleveland 41 44 31 41 22 40 38 40 34 35 30 41 37 40 Cumbria 64 58 30 48 30 41 36 49 47 42 25 43 21 42 Derbyshire 35 41 33 43 28 40 30 30 21 30 28 28 23 27 Devon and Cornwall 30 42 19 35 24 34 18 32 20 33 17 28 19 31 Dorset 25 44 17 27 16 35 17 30 27 28 18 22 11 30 Durham 68 54 71 71 60 63 26 41 43 43 43 47 44 47 Dyfed-Powys 91 89 25 48 31 39 18 42 28 38 20 32 31 49 Essex 32 41 29 39 27 41 25 33 25 40 19 32 19 29 Gloucestershire 31 42 28 35 28 34 19 31 21 34 30 26 23 34 Greater Manchester 46 49 32 40 30 29 31 37 31 35 38 25 31 26 Gwent 80 80 78 80 51 60 40 54 36 35 20 25 38 29 Hampshire 41 53 34 39 25 37 21 33 19 27 21 31 21 29 Hertfordshire 50 50 50 54 38 50 41 42 28 35 22 39 17 36 Humberside 23 38 20 31 19 33 23 35 24 29 22 33 28 31 Kent 38 44 27 38 22 32 21 31 23 26 26 30 22 35 Lancashire 52 54 35 41 37 43 35 44 37 42 30 44 36 42 Leicestershire 26 32 28 32 23 31 18 33 20 26 12 27 17 28 Lincolnshire 40 32 28 36 31 41 21 38 24 32 17 30 25 30 London, City of 100 41 — 28 — 52 — 43 — 33 — 19 100 59 Merseyside 47 52 43 45 35 44 24 41 28 42 22 33 29 34 Metropolitan Police 29 25 33 24 38 26 36 27 34 20 34 21 34 28 Norfolk 24 33 18 42 22 35 23 37 24 36 21 35 36 39 Northamptonshire 53 52 37 55 32 50 33 37 25 36 21 23 19 36 Northumbria 36 46 30 43 24 36 29 44 33 45 29 39 34 41 North Wales 26 34 29 39 27 42 25 47 16 39 17 34 18 36 North Yorkshire 43 55 41 51 35 48 29 50 41 44 26 40 27 35 Nottinghamshire 34 39 27 36 35 38 27 38 31 38 25 30 19 29 South Wales 62 56 53 49 59 40 29 36 28 30 42 37 39 36 South Yorkshire 40 42 38 42 29 37 24 34 27 28 34 30 38 33 Staffordshire 40 48 32 49 30 45 26 37 24 35 21 29 24 27 Suffolk 30 51 26 35 19 31 24 38 20 43 19 33 16 34 Surrey 32 40 35 39 24 40 32 38 29 44 24 39 12 22 Sussex 26 39 24 39 14 32 20 34 15 36 21 30 19 29 Thames Valley 27 32 18 33 24 33 22 32 19 30 19 23 18 21 Warwickshire 27 45 19 30 25 36 19 40 16 31 22 30 28 27 West Mercia 37 46 35 48 29 43 27 48 20 35 22 31 23 32 West Midlands 41 36 32 32 26 27 30 29 23 27 25 27 30 34 West Yorkshire 42 44 31 33 25 34 25 22 19 32 24 25 22 23 Wiltshire 37 40 41 37 32 40 33 38 18 33 23 28 35 31 England and Wales 36 39 31 36 29 34 27 34 26 31 26 29 26 30 1 The data in this table takes account of the introduction of the National Crime Recording Standard in April 2002. These figures are not directly comparable with those for earlier years. Note: Offences detected in any given year may have been initially recorded in a previous year and for this reason some percentages may exceed 100.