Nevada County nonprofits help the arts community thrive and down-on-their-luck residents survive, from troubled youth needing more guidance to the seriously ill in the final stages of life. And local nonprofits greatly depend on donations from businesses and residents, ensuring the less fortunate get the help they need. Overall, we’re a rather generous group in Nevada County, where people donate four percent of their annual income — or about $2,200 a person — per year to local nonprofits, from churches to food pantries and animal welfare centers, according to the Chronicle of Philanthropy. The commitment and those dollars have a …