--FOR SQL SERVER 2016+
DECLARE @str VARCHAR(100) = 'YR:136;YR:50;JN:275;YM:138;IN:477;WO:150;G1:10;F2:10'
SELECT SUBSTRING(value,0,CHARINDEX(':',value,0)) Id
, SUBSTRING(value,CHARINDEX(':',value,0)+1,100) Vals
FROM STRING_SPLIT(@str, ';')
--FOR Older SQL SERVER
DECLARE @x AS XML=''
SET @x = CAST('<A>'+ REPLACE(@str,';','</A><A>')+ '</A>' AS XML)
SELECT SUBSTRING(t.value('.', 'VARCHAR(MAX)') ,0,CHARINDEX(':',t.value('.', 'VARCHAR(MAX)') ,0)) Id
, SUBSTRING(t.value('.', 'VARCHAR(MAX)') ,CHARINDEX(':',t.value('.', 'VARCHAR(MAX)') ,0)+1,100) Vals
FROM @x.nodes('/A') AS x(t)