More than 900 women were killed by men in England and Wales over a six-year period, most by their current or former partners, according to the first detailed analysis of deadly male violence against women in those countries.

The Femicide Census, which tracks and analyses the deaths of women killed by partners, ex-partners, male relatives, acquaintances, colleagues and strangers, was developed by nia, a charity dedicated to ending violence against women, and Women’s Aid.

Between 2009 and 2015, 936 women were killed by men, the census found. Of these, 598 (64%) were killed by their current or former partners and 75 (8%) by their sons.

Polly Neate, the chief executive of Women’s Aid, said: “The killing of women, especially when women are killed by an abusive partner or ex-partner, is often reported as an isolated incident. There is an abject failure to look at patterns of behaviour.

“We accept fatal male violence as an inevitability, not a conscious choice that a man has made to end a woman’s life. This dangerous culture needs to change. We need to learn the lessons. And by viewing these cases of femicide altogether, we can learn.

Facebook Twitter Pinterest Polly Neate of Women’s Aid. Photograph: Sam Friedrich/The Guardian

“Our initial analysis shows that these killings are not isolated incidents; too many of them followed a similar pattern of violence and were premeditated. Many were committed in similar settings, similar weapons were used, and similar relationships existed between the perpetrators and victims.”

Just under half of the women were killed by knives. A sharp instrument was used in 426 cases of femicide, defined as the killing of women because they are women. Killings of women by their partners in a domestic setting made up 290 of those deaths.

Women are at significant risk of deadly violence when they separate from an abusive partner, the figures show. About three-quarters of women killed by their ex-partner or former spouse died within 12 months of their separation.

Women of any age can be victims of femicide. The census found that 149 women aged over 66 were killed in England and Wales over the period.

Femicide is a leading cause of premature death for women, but there is limited research on the issue, according to the groups behind the census.

The 2011 Global Study on Homicide by the UN Office on Drugs and Crime indicated that while there had been a decrease in the number of homicides worldwide, the number of femicides had risen.

The Femicide Census was developed by Karen Ingala Smith, the chief executive of nia, and Women’s Aid, with support from Freshfields Bruckhaus Deringer LLP and Deloitte LLP.

The partnership is calling on the government to take urgent action, including ensuring that specialist domestic abuse and sexual violence services have sustainable, long-term funding, and funding is available for specialist projects for women to move away from prostitution. They also want the relevant authorities to recognise that women are particularly at risk when leaving abusive relationships.

Ingala Smith said: “I started counting dead women back in January 2012. In the first three days of the year, eight women were killed at men’s hands: three shot, two stabbed, two beaten and strangled, and one women killed by her grandson, inflicting 15 blunt force trauma injuries.

“I made a note of their names, just to help me count, and then once I’d started, it didn’t seem right to stop. When can you say that the next woman doesn’t count?

“Looking at official statistics, it was overwhelmingly clear that we were not naming man’s fatal violence against women and we were not counting its full extent. The Femicide Census reveals the bigger picture.”