#include <a_samp>

enum E_PLAYER_STATS // Percentages (between 0 - 100)
{
    Float:pStat_fat,
    Float:pStat_stamina,
    Float:pStat_muscle,
    Float:pStat_respect,
    Float:pStat_sexappeal
};

new PlayerStats[MAX_PLAYERS][E_PLAYER_STATS];

ChangePlayerStat(playerid, E_PLAYER_STATS:stat, Float:amount)
{
    PlayerStats[playerid][stat] += amount;

    if(PlayerStats[playerid][stat] > 100) PlayerStats[playerid][stat] = 100; // First line in question
    if(PlayerStats[playerid][stat] < 0) PlayerStats[playerid][stat] = 0; // Second line in question

    return 1;
}

stock PrintPlayerRespect(playerid) printf("pStat_respect = %.2f", PlayerStats[playerid][pStat_respect]);

public OnFilterScriptInit()
{
    ChangePlayerStat(0, pStat_respect, 69);

    PrintPlayerRespect(0);
}