Croatia is categorised as having established a very high level of human development in the Human Development Index, with a high degree of equality in HDI achievements between women and men. It promotes disability rights. Recognition of same-sex unions in Croatia has gradually improved over the past decade, culminating in registered civil unions in July 2014, granting same-sex couples equal inheritance rights, tax deductions, and limited adoption rights. However, in December 2013 Croatians voted in a constitutional referendum and approved changes to the constitution to define marriage as a union between a man and a woman.