For what reason Scotland reportedly has the highest COVID-19 care home death rate, proportionately per population size, in the UK.

National Records of Scotland (NRS), Northern Ireland Statistics and Research Agency (NISRA) and Office for National Statistics (ONS) publish statistics on deaths where Covid-19 was mentioned on the death certificate (including suspected COVID-19 deaths).
Due to differences in recording and diagnosis the most accurate figures to use to make comparisons in relation to the number and rate of deaths from Covid in any environment are those for all excess deaths over a particular period. Comparisons should also take account of differences in the demographics of care home residents across the UK.
Excess deaths are the total number of deaths registered in a week in 2020 minus the average number of deaths registered in the same week over the period 2015 to 2019. For all parts of the UK, figures are available for excess deaths from all causes, including Covid-19.
During weeks 11-25 of 2020, excess deaths in care homes in England and Wales have been 83% above the five year average compared to 66% for Scotland.
NRS statistics show Covid-19 deaths in care homes, year-to-date up to 21 June (week 25) as being 47% of Scotland’s deaths from Covid-19. NISRA statistics for this period also show 42% of deaths from Covid-19 in Northern Ireland as being in care homes. The percentage of Covid-19 related deaths occurring in care homes in Scotland is broadly in line with many other European countries.