By Francesco Zecchini ROME (Reuters) – Italy’s population will shrink by 5 million within 30 years unless decisive steps are taken to increase the number of births, the head of the country’s statistics institute ISTAT warned on Thursday. The COVID-10 pandemic hastened a long-running decline in Italy’s birthrate, ISTAT reported in March, with 399,431 births registered in 2021 against 404,892 in 2020. That marked the 13th consecutive yearly fall and the lowest number since the unification of Italy in 1861. The population fell by 253,000 to 59 million. “If the fertility rate remains around the cu…