Delta variant mildest of all 7 variants tracked in the UK

https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/994997/Variants_of_Concern_VOC_Technical_Briefing_16.pdf 

Data current to June 11, official UK government report

Table 2. Number of confirmed (sequencing) and probable (genotyping) cases by variant as of 14 June 2021

Variant	Confirmed (sequencing) case number	Probable (genotyping) case number*	Total case number	Case Proportion*	Deaths	Case Fatality	Cases with 28 day follow up	Deaths among those with 28 day follow up	Case Fatality among those with 28 day follow up
Alpha	218,332	5,689	224,021	77.9%	4,259	1.9% (1.8 to 2.0%)	217,228	4,252	2.0% (1.9 to 2.0%)
Beta	871	55	926	0.3%	13	1.4% (0.7 to 2.4%)	858	13	1.5% (0.8 to 2.6%)
Delta	31,132	29,523	60,655	21.1%	73	0.1% (0.1 to 0.2%)	5,762	17	0.3% (0.2 to 0.5%)
Eta	441	0	441	0.2%	12	2.7% (1.4 to 4.7%)	428	12	2.8% (1.5 to 4.8%)
Gamma	170	42	212	0.1%	0	0.0% (0.0 to 1.7%)	155	0	0.0% (0.0 to 2.4%)
Kappa	422	0	422	0.1%	1	0.2% (0.0 to 1.3%)	404	1	0.2% (0.0 to 1.4%)
Theta	7	0	7	0.0%	0	0.0% (0.0 to 41.0%)	5	0	0.0% (0.0 to 52.2%)