MARKWEST ENERGY PARTNERS L P

CUSIP: 570759100 Class: UNIT LP PARTN

DUFF & PHELPS INVESTMENT MANAGEMENT CO's Holding History (CIK: 0000765443)

Note: Option positions (PUT/CALL) are excluded.

Q3 2015
Shares 1,271,500 Value ($000) $54,560 Avg Close — Range —
Q2 2015
Shares 1,365,500 Value ($000) $76,987 Avg Close — Range —
Q1 2015
Shares 1,370,500 Value ($000) $90,590 Avg Close — Range —
Q4 2014
Shares 1,329,500 Value ($000) $89,329 Avg Close — Range —
Q3 2014
Shares 1,279,000 Value ($000) $98,253 Avg Close — Range —
Q2 2014
Shares 1,279,000 Value ($000) $91,551 Avg Close — Range —
Q1 2014
Shares 723,000 Value ($000) $47,226 Avg Close — Range —
Q4 2013
Shares 622,000 Value ($000) $41,133 Avg Close — Range —
Q3 2013
Shares 622,000 Value ($000) $44,927 Avg Close — Range —
Q2 2013
Shares 622,000 Value ($000) $41,581 Avg Close — Range —