--The Analysis: my crappy assumptions:
--UPDATE STATISTICS dbo.GMPVDET 
--tables under 1000 rows, I'll leave then at 20%
--tables with more rows than that, I'll use an arbitrary sliding scale formula.
--formula to be modified  based on analysis
SELECT X.*,
  ISNULL(CASE
    WHEN X.[Total Rows]<=1000
    THEN
      CASE 
        WHEN [Percent Modified] >=20.0
        THEN 'UPDATE STATISTICS ' + [Schema Name] + '.' + [Table Name] + ' WITH ALL, FULLSCAN  --20% Small Table Rule'
      END
    WHEN [Percent Modified] = 100.00
    THEN 'UPDATE STATISTICS ' + [Schema Name] + '.' + [Table Name]     + ' WITH ALL, FULLSCAN  --100% No real Stats Rule'
    --WHEN X.[Rows Modified] > 1000
    --THEN 'UPDATE STATISTICS ' + [Schema Name] + '.' + [Table Name]     + ' WITH ALL, FULLSCAN  --1000 Rows Modified Rule'
    ELSE 
      CASE 
        WHEN X.[Total Rows] > 1000000000 --billion rows
        THEN CASE
               WHEN [Percent Modified] > 0.1
               THEN 'UPDATE STATISTICS ' + [Schema Name] + '.' + [Table Name]     + ' WITH ALL, FULLSCAN  -- 1B Big Table Rule'
             END
        WHEN X.[Total Rows] > 100000000  --hundred million rows
        THEN CASE
               WHEN [Percent Modified] > 1.0
               THEN 'UPDATE STATISTICS ' + [Schema Name] + '.' + [Table Name]     + ' WITH ALL, FULLSCAN  -- 100M Big Table Rule'
             END
        WHEN X.[Total Rows] > 10000000   --ten million rows
        THEN CASE
               WHEN [Percent Modified] > 2.0
               THEN 'UPDATE STATISTICS ' + [Schema Name] + '.' + [Table Name]     + ' WITH ALL, FULLSCAN  -- 10M Big Table Rule'
             END
        WHEN X.[Total Rows] > 1000000    --million rows
        THEN CASE
               WHEN [Percent Modified] > 5.0
               THEN 'UPDATE STATISTICS ' + [Schema Name] + '.' + [Table Name]     + ' WITH ALL, FULLSCAN  -- 1M Big Table Rule'
             END
        WHEN X.[Total Rows] > 100000     --hundred thousand rows
        THEN CASE
               WHEN [Percent Modified] > 10.0
               THEN 'UPDATE STATISTICS ' + [Schema Name] + '.' + [Table Name]     + ' WITH ALL, FULLSCAN  -- 100K Big Table Rule'
             END
        WHEN X.[Total Rows] > 10000      --ten thousand rows
        THEN CASE
               WHEN [Percent Modified] > 20.0
               THEN 'UPDATE STATISTICS ' + [Schema Name] + '.' + [Table Name]     + ' WITH ALL, FULLSCAN  -- 10K Big Table Rule'
             END
        END
  END,'') AS [Statistics SQL]
FROM (
SELECT  DISTINCT
        DB_NAME()   AS [Database],
        S.name      AS [Schema Name],
        T.name      AS [Table Name],
        I.rowmodctr AS [Rows Modified],
        P.rows      AS [Total Rows],
        CASE 
          WHEN I.rowmodctr > P.rows
          THEN 100
          ELSE CONVERT(decimal(8,2),((I.rowmodctr * 1.0) / P.rows * 1.) * 100.0)
        END AS [Percent Modified]
FROM 
        sys.partitions P 
        INNER JOIN sys.tables  T ON P.object_Id = T.object_id 
        INNER JOIN sys.schemas S ON T.schema_id = S.schema_id
        INNER JOIN sysindexes  I ON P.object_id = I.id
WHERE P.index_id in (0,1)
  AND I.rowmodctr > 0
) X
WHERE [Rows Modified] > 1000
ORDER BY [Rows Modified] DESC

DECLARE @statistic_name SYSNAME = N'_WA_Sys_00000002_7D78A4E7',
    @table_name SYSNAME= N'activity_snapshot',
    @schema_name SYSNAME = N'dbo';

SELECT  STATS_DATE(st.object_id, st.stats_id) AS [LastUpdated]
FROM    sys.tables AS tbl
        INNER JOIN sys.stats st ON st.object_id = tbl.object_id
WHERE   (st.name = @statistic_name)
        AND (
             (tbl.name = @table_name
             AND SCHEMA_NAME(tbl.schema_id) = @schema_name )
            );

UPDATE STATISTICS dbo.activity_snapshot _WA_Sys_00000002_7D78A4E7;

We walk in the dark places no others will enter
We stand on the bridge and no one may pass

We walk in the dark places no others will enter
We stand on the bridge and no one may pass

We walk in the dark places no others will enter
We stand on the bridge and no one may pass