Symbolic number falls short of a full equation: David McKittrick examines the unrelenting toll of violence during more than 20 years of the Troubles

THE figure of 3,000 deaths is largely symbolic, as there is no universally agreed statistic on the number of people killed in the Troubles. This particular figure comes from the RUC, but it omits several controversial deaths and the killings outside Northern Ireland.

It excludes, among others, a republican suspect who hanged himself in police custody in 1978, and the RUC officer who committed suicide after killing three men in a Sinn Fein office in Belfast this year.

If deaths outside the province are included, the figure rises to well past 3,000, as there have been more than 100 deaths in Britain, exactly 100 in the Irish Republic and 18 on the Continent.

Similarly, there are no definitive figures for the numbers killed by each agency active in Northern Ireland - the republicans, the extreme loyalists and the security forces. Until a few years ago, the authorities listed the number of killings carried out by republicans and loyalists, but they have now stopped this practice.

The most useful figures have been compiled by a retired Belfast teacher, Michael McKeown, but no truly authoritative study has yet emerged. An estimate can be made, however, using Mr McKeown's figures together with those the RUC once issued, and files kept by the Independent.

There are so many unclear killings, however, that the following estimates should be regarded as guidelines rather than accurate figures:

Killed by republicans: 1,720

Killed by loyalists: 780

Killed by security forces: 350

Others/unclassified: 150

The republican total is mainly made up of IRA killings, together with a much smaller number of victims of two splinter groups, the Irish National Liberation Army and the Irish People's Liberation Organisation.

Killings in the republic have been carried out by republicans and loyalists, while deaths on the Continent are almost entirely the responsibility of the former.

More than 90 per cent of loyalist killings are believed to be the work of the two main extreme Protestant groupings, the Ulster Volunteer Force and the Ulster Defence Association.

The RUC classifies the dead as either members of the security forces or civilians, but the latter category is diverse, and contains former members of the security forces, prison officers, judges and magistrates, suspected terrorists, those shot as informers and others.

The pattern of deaths has changed greatly over the years. The security forces have never looked like eradicating the violence, but in the past 15 years the toll has not exceeded 113 in any one year. Compared with pre-1977 death rates, it can be argued that even that level of death represents success of a sort for a policy of containment.

Almost half of all deaths, 1,477, occurred from 1972 to 1976 when violence rose to heights not seen since.

Last year was considered a bad one with 94 deaths, but in 1972, 95 people were killed in July alone. The total for that year was 467, with the regular Army suffering 103 casualties. There were more than 10,000 shooting incidents - an average of 29 per day - and an average of nearly four explosions per day.

Since 1977, the security forces, while unable to defeat the paramilitary groups, have held the violence to a certain level. The terrorists remain unbeaten, but they lack the capacity to render Northern Ireland ungovernable.

The net result is a stalemate: neither the authorities nor the terrorists have the upper hand. The death rate rises and falls, but does so within certain statistical limits. One of the few consolations is the thought that, bad as things have been, it could all have been much worse.