(Bloomberg) -- For all the talk of a slowdown in the US economy, more than a dozen US states have the best job markets in their history. Unemployment rates were lower last month than a year earlier in 23 states, and stable in another seven, according to data released Friday by the Bureau of Labor Statistics. In 15 states, unemployment was at the lowest level since the data series began in January 1976, and in 40 of them there was a statistically significant increase in the number of people working over the 12 months through April. In California, often seen a bellwether for the wider US economy, the unemployment rate has climbed 0.4 percentage point over the past year. © Source: Bureau of Labor Statistics State Unemployment Rates in April | In 29 states, the unemployment rate is below the US average of 3.4%South Dakota had the lowest jobless rate in April, at 1.9%.