/**
 * Get the index to use for pluralization.
 *
 * The plural rules are derived from code of the Zend Framework (2010-09-25), which
 * is subject to the new BSD license (https://framework.zend.com/license)
 * Copyright (c) 2005-2010 - Zend Technologies USA Inc. (http://www.zend.com)
 */
export declare function getPluralIndex(lang: string, number: number): number;