1)
mysql> SELECT COUNT(*) FROM (SELECT 1 FROM abuse_filter_history GROUP BY afh_filter) as filters;
+----------+
| COUNT(*) |
+----------+
|       50 |
+----------+
1 row in set (0.00 sec)

2)
mysql> SELECT abusefilter_hit.count/all_edits.count as abusefilter_triggered FROM (SELECT edits.count + disallowed.count as count FROM (SELECT COUNT(*) as count FROM recentchanges) as edits, (SELECT COUNT(*) as count FROM abuse_filter_log WHERE afl_timestamp > (SELECT MIN(rc_timestamp) FROM recentchanges) AND afl_actions LIKE "%disallow%") as disallowed) as all_edits, (SELECT COUNT(*) as count FROM abuse_filter_log WHERE afl_timestamp > (SELECT MIN(rc_timestamp) FROM recentchanges)) as abusefilter_hit;
+-----------------------+
| abusefilter_triggered |
+-----------------------+
|                0.0073 |
+-----------------------+
1 row in set (0.19 sec)

3)
mysql> SELECT afh_user_text, COUNT(*) FROM abuse_filter_history INNER JOIN (SELECT MIN(afh_id) as id FROM abuse_filter_history GROUP BY afh_filter) as first_edit ON afh_id = first_edit.id GROUP BY afh_user_text;
+----------------+----------+
| afh_user_text  | COUNT(*) |
+----------------+----------+
| Billinghurst   |        1 |
| Bsadowski1     |        1 |
| Dferg          |        7 |
| Herbythyme     |        4 |
| Hillgentleman  |        1 |
| Jafeluv        |        1 |
| Kanonkas       |        1 |
| MZMcBride      |        1 |
| Matanya        |        1 |
| Mike.lifeguard |       19 |
| Shizhao        |        3 |
| Trijnstel      |        6 |
| VasilievVV     |        1 |
| Vituzzu        |        3 |
+----------------+----------+
14 rows in set (0.00 sec)

4)
mysql> SELECT afh_filter, afh_user_text as creator, abusefilter_hit.count/all_edits.count as abusefilter_triggered FROM (SELECT edits.count + disallowed.count as count FROM (SELECT COUNT(*) as count FROM recentchanges) as edits, (SELECT COUNT(*) as count FROM abuse_filter_log WHERE afl_timestamp > (SELECT MIN(rc_timestamp) FROM recentchanges) AND afl_actions LIKE "%disallow%") as disallowed) as all_edits, abuse_filter_history INNER JOIN (SELECT MIN(afh_id) as id FROM abuse_filter_history GROUP BY afh_filter) as first_edit ON afh_id = first_edit.id LEFT JOIN (SELECT COUNT(*) as count, afl_filter FROM abuse_filter_log WHERE afl_timestamp > (SELECT MIN(rc_timestamp) FROM recentchanges) GROUP BY afl_filter) as abusefilter_hit ON abusefilter_hit.afl_filter = afh_filter GROUP BY afh_filter;
+------------+----------------+-----------------------+
| afh_filter | creator        | abusefilter_triggered |
+------------+----------------+-----------------------+
|          1 | Hillgentleman  |                  NULL |
|          2 | Mike.lifeguard |                  NULL |
|          3 | Mike.lifeguard |                  NULL |
|          4 | Mike.lifeguard |                  NULL |
|          5 | Mike.lifeguard |                  NULL |
|          6 | Mike.lifeguard |                0.0001 |
|          7 | Mike.lifeguard |                0.0009 |
|          8 | Mike.lifeguard |                  NULL |
|          9 | Mike.lifeguard |                  NULL |
|         10 | Mike.lifeguard |                  NULL |
|         11 | Mike.lifeguard |                0.0000 |
|         12 | Kanonkas       |                  NULL |
|         13 | Shizhao        |                  NULL |
|         14 | Shizhao        |                  NULL |
|         15 | Shizhao        |                  NULL |
|         16 | Mike.lifeguard |                  NULL |
|         17 | Mike.lifeguard |                  NULL |
|         18 | Mike.lifeguard |                  NULL |
|         19 | Mike.lifeguard |                  NULL |
|         20 | Mike.lifeguard |                  NULL |
|         21 | Mike.lifeguard |                  NULL |
|         22 | Mike.lifeguard |                  NULL |
|         23 | Dferg          |                  NULL |
|         24 | Dferg          |                  NULL |
|         25 | Mike.lifeguard |                  NULL |
|         26 | Dferg          |                  NULL |
|         27 | Dferg          |                  NULL |
|         28 | Mike.lifeguard |                  NULL |
|         29 | Dferg          |                  NULL |
|         30 | VasilievVV     |                  NULL |
|         31 | Dferg          |                0.0001 |
|         32 | Bsadowski1     |                  NULL |
|         33 | Matanya        |                  NULL |
|         34 | Trijnstel      |                  NULL |
|         35 | Trijnstel      |                0.0004 |
|         36 | Trijnstel      |                0.0007 |
|         37 | Trijnstel      |                0.0001 |
|         38 | Trijnstel      |                0.0001 |
|         39 | Jafeluv        |                0.0023 |
|         40 | Dferg          |                0.0001 |
|         41 | Vituzzu        |                  NULL |
|         42 | MZMcBride      |                  NULL |
|         43 | Trijnstel      |                0.0010 |
|         44 | Herbythyme     |                0.0005 |
|         45 | Vituzzu        |                0.0002 |
|         46 | Herbythyme     |                  NULL |
|         47 | Herbythyme     |                  NULL |
|         48 | Vituzzu        |                  NULL |
|         49 | Billinghurst   |                0.0005 |
|         50 | Herbythyme     |                0.0003 |
+------------+----------------+-----------------------+
50 rows in set (0.02 sec)