Hello again friends, sorry about the double post - I was having issues editing my earlier post.
$auditSample = Import-CSV .\sampleData.csv
$auditSample
Name IRNumber
---- --------
Last, First1 Not Found
Last, First2 Not Found
Last, First3 Not Found
Last, First4 Not Found
Last, First5 Not Found
Last, First6 Not Found
Last, First7 Not Found
Last, First8 Not Found
Last, First9 Not Found
Last, First10 Not Found
Last, First01 Service Account
Last, First02 Service Account
Last, First03 Service Account
Last, First04 Service Account
Last, First05 Service Account
Last, First06 Service Account
Last, First07 Service Account
Last, First08 Service Account
Last, First09 Service Account
Last, First10 Service Account
Last, First 20 Local Admin Account
Last, First 21 Local Admin Account
Last, First 22 Local Admin Account
Last, First 23 Local Admin Account
Last, First 24 Local Admin Account
Last, First 25 Local Admin Account
Last, First 26 Local Admin Account
Last, First 27 Local Admin Account
Last, First 28 Local Admin Account
Admin1 Domain Admin
Admin2 Domain Admin
Admin3 Domain Admin
Last, First 36 IR56242
Last, First 43 IR56242
Last, First 46 IR56242
Last, First 48 IR56242
Last, First 55 IR56242
Dux, Frank IR56242
Last, First 70 IR56242
Last, First 70 IR56242
Last, First 70 IR56242
Last, First 70 IR56242
Last, First 70 IR56242
Last, First 70 IR56242
Last, First 70 IR56242
Last, First 70 IR56242
Last, First 70 IR56242
Last, First 70 IR56242
Last, First 70 IR56242
Last, First 70 IR56242
Last, First 50 IR44372
Last, First 33 IR42115
Last, First 32 IR29068
Last, First 32 IR29068
Last, First 32 IR29068
Last, First 40 IR27733
Last, First 49 IR243582
Last, First 37 IR243581
$auditSample | Group-Object -Property IRNumber -NoElement | Sort-Object -Property Count -Descending
Count Name
----- ----
18 IR56242
10 Not Found
10 Service Account
9 Local Admin Account
3 Domain Admin
3 IR29068
1 IR44372
1 IR42115
1 IR27733
1 IR243582
1 IR243581