CDC website (direct link to 6%):
https://www.cdc.gov/nchs/nvss/vsrr/covid_weekly/index.htm?fbclid=IwAR2-muRM3tB3uBdbTrmKwH1NdaBx6PpZo2kxotNwkUXlnbZXCwSRP2OmqsI#Comorbidities
Comorbidities:
Table 3 shows the types of health conditions and contributing causes mentioned in conjunction with deaths involving coronavirus disease 2019 (COVID-19).
For 6% of the deaths, COVID-19 was the only cause mentioned.
Excess deaths:
https://www.cdc.gov/nchs/nvss/vsrr/covid19/excess_deaths.htm