According to this source transrespect.org/en/map/trans-murder-monitoring/, 8 transgender people have been murdered in the UK since 2008

Their list (taken from various PDFs on their site):

2015
Vikki Thompson - not murder but accidental death, initially reported as suicide www.theguardian.com/uk-news/2017/may/19/jury-returns-verdict-on-transgender-woman-found-dead-in-male-prison

Vanessa Santillan - killed by husband because of sex work www.bbc.co.uk/news/uk-england-london-34591733

2013
Jacqueline Cowdrey - found NOT to have been murdered www.bbc.co.uk/news/uk-england-sussex-26145984

2012
Chrissie Azzopardi - killed over drug debts www.theguardian.com/uk-news/2013/oct/18/chrissie-azzopardi-murder-life-sentence

2011
Lionel/Suzie Morl - described as transvestite, murdered by two Big Issue sellers (male & female) to live off his disability benefits www.manchestereveningnews.co.uk/news/greater-manchester-news/guilty-couple-who-killed-transvestite-689598

2010
Sonia/David Burgess gender fluid lawyer killed by a gender fluid/trans client www.bbc.co.uk/news/uk-england-london-16305570

2009
Andrea Waddell
www.getreading.co.uk/news/local-news/andrea-waddell-strangled-client-4226743 - sex worker killed by customer. Customer claimed not to know Waddell was transsexual. "During the trial, jurors were asked to consider whether McMillan killed her after discovering she was transgender, or because she was unable to perform sexually for him because of physical ailments after illnesses including fibromyalgia."

Destiny Lauren sex worker - killed by customer www.islingtongazette.co.uk/news/life-sentence-for-killer-of-transsexual-prostitute-destiny-lauren-1-680308 Customer had previously sought the services of transsexual prostitutes going by the names of "Fransexual" and "VickisDomain"

So in summary, not 8 murders but 6, of which:

3 were sex workers killed because of their sex work
2 were killed for financial reasons
1 was killed by another transgender person

"A total of 152 UK sex workers have been murdered since 1990. According to the charity National Ugly Mugs, 85% of street prostitutes have experienced violence and only 25% of victims are willing to report crimes to the police."

news.sky.com/story/sex-workers-still-vulnerable-10-years-after-ipswich-murders-10679614

There were around 571 homicides in the last year in England & Wales, that's approximately 1 per 100,000 people.

Thus over the 9 years 2008 to 2016, given six homicides, that implies a transgender murder rate of 0.67 per year, assuming transgender people are as likely to be killed as the rest of the country. That would suggest that there are only 67,000 transgender people in England & Wales.

However, the LOWEST estimate for transgender people is 0.1% (so around 57,000), and GIRES says it is 0.2% at the very minimum (so around 114,000).

Obviously given the tiny numbers you can't be too specific with these statistics, we aren't taking about a population (of murdered trans people) so much as vanishingly rare cases.

With regard to sex work, there are apparently around 72,800 sex workers in the UK of which 4% (approx 2900 are transgender). en.wikipedia.org/wiki/Prostitution_in_the_United_Kingdom#Extent

Given the overall sex worker murder rate of ~6 per year, that implies 1 in every 12,000 sex workers will be murdered in any given year. Therefore given the 2900*9 = 26,100 transgender sex worker years in the period under study, we'd expect 26100/12000 = 2.175 murders of transgender sex workers. The total of 3 is very slightly above average in that respect, however statistically it's not even remotely significant (5 would be significant at the 95% confidence interval). I am not 100% clear if the case of Vanessa Santillan is included within the figures, as Santillan was murdered not by a client, but a jealous husband.

Also note that in general 1 in 780 people are sex workers (and sex workers have a homicide rate 8 times higher than the general population) but as many as 1 in 20 transgender people may be sex workers, so there will be a higher rate of murder.

Moreover, all of the murders were biologically male (and indeed most transgender people are male). The male murder rate is around 75% higher than the female murder rate in the country as a whole.