Shares of West Pharmaceutical Services (WST) have been strong performers lately, with the stock up 27% over the past month. The stock hit a new 52-week high of $328.44 in the previous session. West Pharmaceutical has gained 18.5% since the start of the year compared to the -8.2% move for the Zacks Medical sector and the -11% return for the Zacks Medical - Dental Supplies industry.What's Driving the Outperformance?The stock has an impressive record of positive earnings surprises, as it hasn't missed our ear ...