FBL Financial Group Inc. on Thursday reported double-digit increases in second-quarter earnings compared with the year-ago period. The West Des Moines insurer had net income of $29.6 million, or $1.13 per share, for the quarter, compared with $20.3 million, or 73 cents per share, for the second quarter of 2012. Strong results from its Farm Bureau Life subsidiary, higher investment fee income, favorable stock market performance and better than expected mortality experience were among the factors the company cited for a 36 percent increase in operating income. "Our strategies of driving life insurance sales, managing expenses and maintaining a strong capital position produced another quarter of results that exceed expectations," CEO James Brannen said in a release.