MARKWEST ENERGY PARTNERS L P

CUSIP: 570759100 Class: UNIT LP PARTN

MASON STREET ADVISORS, LLC's Holding History (CIK: 0001167711)

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

Q4 2014
Shares 400,682 Value ($000) $26,922 Avg Close — Range —
Q3 2014
Shares 190,000 Value ($000) $14,596 Avg Close — Range —
Q2 2014
Shares 360,000 Value ($000) $25,769 Avg Close — Range —
Q1 2014
Shares 328,200 Value ($000) $21,438 Avg Close — Range —
Q4 2013
Shares 328,200 Value ($000) $21,704 Avg Close — Range —
Q3 2013
Shares 246,400 Value ($000) $17,797 Avg Close — Range —
Q2 2013
Shares 279,900 Value ($000) $18,711 Avg Close — Range —